W4HM Daily HF Radio Wave Propagation Forecast

W4HM Daily HF Radio Wave Propagation Forecast

#2018-139

Thomas Giella All Messages By This Member #60 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in both disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #139 Issued Sunday May 20, 2018 at 1630 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 70.3 70.3 70.0 There had been 1 day with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. Prior to that there had been 3 days with a 2000 UTC daily solar flux index number (DSFI) of lower than 70. The official daily sunspot number (DSSN) was 0. There had been 6 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 79 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 0 0 0 0 1 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 356 & 327 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 20, 2018- steady. HF radio wave propagation condition “trend” May 21, 2018- steady. HF radio wave propagation condition “trend” May 22, 2018- deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #61 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in both disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #140 Issued Monday May 21, 2018 at 1400 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 68.7 68.8 68.5. There had been 1 day with a 2000 UTC daily solar flux index number (DSFI) lower than 70. The official daily sunspot number (DSSN) was 0. There had been 7 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 1 1 0 1 0 0 0. The 24 hour period maximum and minimum solar wind speed ranged between 353 & 324 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 21, 2018- steady. HF radio wave propagation condition “trend” May 22, 2018- steady then deteriorating. HF radio wave propagation condition “trend” May 23, 2018- deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #62 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in both disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #141 Issued Tuesday May 22, 2018 at 1400 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 68.9 69.6 68.9 There had been 2 days with a 2000 UTC daily solar flux index number (DSFI) lower than 70. The official daily sunspot number (DSSN) was 12. (((((Newly risen sunspot group #12710 was located near N08E68 with a relatively simple beta magnetic signature capable of releasing a very, very small in size A class solar flare and a very small in size B class solar flare.))))) There had been 7 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 0 1 1 1 0 1 0 1 The 24 hour period maximum and minimum solar wind speed ranged between 322 & 309 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 22, 2018- steady. HF radio wave propagation condition “trend” May 23, 2018- steady then deteriorating. HF radio wave propagation condition “trend” May 24, 2018- deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #63 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in both disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #142 Issued Wednesday May 23, 2018 at 1430 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 70.4 70.8 71.8 There had been 1 day with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 26. (((((Newly emerged sunspot group #12711 was located near N06W22 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare.))))) Sunspot group #12710 was located near N17E45 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare. There had been 2 days in a row with a daily sunspot number (DSSN) of higher than 0. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 1 2 1 2 1 2 2. The 24 hour period maximum and minimum solar wind speed ranged between 514 & 320 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 23, 2018- deteriorating. HF radio wave propagation condition “trend” May 24, 2018- deteriorating. HF radio wave propagation condition “trend” May 25, 2018- improving. Northern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day We are now moving into the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #64 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in both disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #143 Issued Thursday May 24, 2018 at 1430 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 73.0 73.1 72.6 There had been 2 days with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 30. Sunspot group #12711 was located near N06W28 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare. Sunspot group #12710 dissipated into a plage. (((((A new sunspot group may rise above the eastern limb of the sun in the next 1-2 days. It has already released a small in size C2.0 solar flare.))))) There had been 3 days in a row with a daily sunspot number (DSSN) of higher than 0. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet to unsettled geomagnetic condition of 2 2 3 3 3 2 1 2. The 24 hour period maximum and minimum solar wind speed ranged between 548 & 457 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 24, 2018- deteriorating. HF radio wave propagation condition “trend” May 25, 2018- steady. HF radio wave propagation condition “trend” May 26, 2018- improving. Northern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day We are now in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #65 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in both disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #144 Issued Friday May 25, 2018 at 1445 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 73.6 73.7 73.8 There had been 3 days with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 39. This is the highest daily sunspot number (DSSN) in a long time. Sunspot group #12712 was located near N13E75 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare. Sunspot group #12711 was located near N06W41 with a simple alpha magnetic signature capable of releasing a very small in size B class solar flare. Sunspot group #12710 dissipated into a plage. There had been 4 days in a row with a daily sunspot number (DSSN) of higher than 0. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 2 2 1 1 1 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 491 & 370 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 25, 2018- improving. HF radio wave propagation condition “trend” May 26, 2018- improving. HF radio wave propagation condition “trend” May 27, 2018- steady state. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #66 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #145 Issued Saturday May 26, 2018 at 1500 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 74.9 75.7 75.5 The 75.7 is the highest 2000 UTC daily solar flux index number (DSFI) in a long time. There had been 4 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 32. Sunspot group #12712 was located near N15E59 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare. Sunspot group #12711 was located near N07W57 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare. There had been 5 days in a row with a daily sunspot number (DSSN) of higher than 0. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 1 0 0 1 1 1 0. The 24 hour period maximum and minimum solar wind speed ranged between 376 & 328 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 26, 2018- improving. HF radio wave propagation condition “trend” May 27, 2018- steady. HF radio wave propagation condition “trend” May 28, 2018- steady and then deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10-15 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5-10 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #67 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #146 Issued Sunday May 27, 2018 at 1500 UTC Solar activity is very low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 74.5 72.9 73.3 There had been 5 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 26. There had been 6 days in a row with a daily sunspot number (DSSN) of higher than 0. Sunspot group #12712 was located near N15E46 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare. Sunspot group #12711 was located near N06W70 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and a small in size C class solar flare. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 0 1 0 0 1 0 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 348 & 287 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 27, 2018- steady. HF radio wave propagation condition “trend” May 28, 2018- steady. HF radio wave propagation condition “trend” May 29, 2018- steady. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10-15 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5-10 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #68 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #147 Issued Monday May 28, 2018 at 1415 UTC Solar activity is very low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 74.2 74.6 75.1 There had been 6 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 27. There had been 7 days in a row with a daily sunspot number (DSSN) of higher than 0. Sunspot group #12712 was located near N15E32 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and an isolated small in size C class solar flare. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 1 0 1 1 0 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 371 & 305 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 28, 2018- steady. HF radio wave propagation condition “trend” May 29, 2018- deteriorating. HF radio wave propagation condition “trend” May 30, 2018- improving. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10-15 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5-10 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #69 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #148 Issued Tuesday May 29, 2018 at 1600 UTC Solar activity is very low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 77.6 76.9 77.1 There had been 7 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 20. There had been 8 days in a row with a daily sunspot number (DSSN) of higher than 0. Sunspot group #12712 was located near N15E18 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and an isolated small in size C class solar flare. On Monday May 28, 2018 at 1712 UTC #12712 produced a C2.7 solar flare. It also produced 7 very small B class solar flares. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 1 1 1 2 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 431 & 366 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 29, 2018- steady. HF radio wave propagation condition “trend” May 30, 2018- steady. HF radio wave propagation condition “trend” May 31, 2018- steady. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10-15 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5-10 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #70 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #149 Issued Wednesday May 30, 2018 at 1530 UTC Solar activity is very low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 76.0 74.9 73.9 There had been 8 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 22. There had been 9 days in a row with a daily sunspot number (DSSN) of higher than 0. Sunspot group #12712 was located near N16E05 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and an isolated small in size C class solar flare. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 2 1 1 1 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 417 & 317 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 30, 2018- steady. HF radio wave propagation condition “trend” May 31, 2018- steady. HF radio wave propagation condition “trend” Jun 1, 2018- deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10-15 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5-10 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #71 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #150 Issued Thursday May 31, 2018 at 1545 UTC Solar activity is very low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 75.1 75.3 74.4 There had been 9 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 18. There had been 10 days in a row with a daily sunspot number (DSSN) of greater than 0. Sunspot group #12712 was located near N16W09 with a relatively simple beta magnetic signature capable of releasing a very small in size B class solar flare and an isolated small in size C class solar flare. #12712 released 6 very small in size B class solar flares. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 1 1 1 1 1 2 2. The 24 hour period maximum and minimum solar wind speed ranged between 370 & 333 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 31, 2018- steady. HF radio wave propagation condition “trend” Jun 1, 2018- steady then deteriorating. HF radio wave propagation condition “trend” Jun 2, 2018- deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S8-9 at day, 21000-21850 kHz- S0 at night and S4-7 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S0-1 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9+10-15 at night and S4-7 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+5-10 at night and S5-8 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S1-3 at night and S9+1 at day, 21000-21850 kHz- S0 at night and S5-8 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1-3 at day, 28000-29700 kHz- S0 at night and S1 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #72 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #151 Issued Friday Jun 1, 2018 at 1500 UTC Solar activity is low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 77.3 76.8 75.9 There had been 10 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 21. There had been 11 days in a row with a daily sunspot number (DSSN) of greater than 0. Sunspot group #12712 was located near N14W22 with a complex beta-gamma magnetic signature capable of releasing a small in size C class solar flare and an isolated medium in size M class solar flare. #12712 released 17 very small in size B class solar flares. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at an active to quiet geomagnetic condition of 1 1 0 1 2 4 4 3. The 24 hour period maximum and minimum solar wind speed ranged between 476 & 294 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 1, 2018- deteriorating. HF radio wave propagation condition “trend” Jun 2, 2018- deteriorating. HF radio wave propagation condition “trend” Jun 3, 2018- steady. Northern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #73 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #152 Issued Saturday Jun 2, 2018 at 1400 UTC Solar activity is low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 77.5 74.8 74.9 There had been 11 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 22. There had been 12 days in a row with a daily sunspot number (DSSN) of greater than 0. Sunspot group #12712 was located near N16W23 with a complex beta-gamma magnetic signature capable of releasing a small in size C class solar flare and an isolated medium in size M class solar flare. #12712 released 5 very small in size B class solar flares. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a minor geomagnetic storming level to unsettled geomagnetic condition of 3 4 4 4 5 4 3 3. The 24 hour period maximum and minimum solar wind speed ranged between 766 & 629 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 2, 2018- deteriorating. HF radio wave propagation condition “trend” Jun 3, 2018- deteriorating. HF radio wave propagation condition “trend” Jun 4, 2018- steady. Northern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #74 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #153 Issued Sunday Jun 3, 2018 at 1530 UTC Solar activity is low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 75.1 74.4 74.2 There had been 12 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 20. There had been 13 days in a row with a daily sunspot number (DSSN) of greater than 0. Decaying sunspot group #12712 was located near N14W34 with a slightly complex beta magnetic signature capable of releasing a very small in size B class solar flare and an isolated small in size C class solar flare. #12712 released 7 very small in size B class solar flares. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at an active to quiet geomagnetic condition of 2 4 3 2 2 2 4 4. The 24 hour period maximum and minimum solar wind speed ranged between 647 & 557 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 3, 2018- steady. HF radio wave propagation condition “trend” Jun 4, 2018- steady. HF radio wave propagation condition “trend” Jun 5, 2018- improving. Northern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast b- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #76 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #155 Issued Tuesday Jun 5, 2018 at 1430 UTC Solar activity is very low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 72.8 70.5 71.7 There had been 15 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 11. (((((But on Tuesday June 5, 2018 sunspot group #12712 has set around the west limb of the sun and the unofficial daily sunspot number (DSSN) is 0.))))) There had been 15 days in a row with a daily sunspot number (DSSN) of greater than 0. Decaying sunspot group #12712 was located near N14W77 with a simple alpha magnetic signature capable of releasing a very very small in size A class solar flare. #12712 released no class solar flares. In 2018 there had been 80 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 1 1 1 0 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 613 & 450 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 5, 2018- improving. HF radio wave propagation condition “trend” Jun 6, 2018- improving. HF radio wave propagation condition “trend” Jun 7 2018- improving. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +5 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 5 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S4-5 at day, 21000-21850 kHz- S0 at night and S2-4 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #77 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #156 Issued Wednesday Jun 6, 2018 at 1600 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 71.5 71.3 70.2 There had been 17 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 0. There had been 1 day with a daily sunspot number (DSSN) of 0. There had been 15 days in a row with a daily sunspot number (DSSN) of greater than 0. In 2018 there had been 81 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 2 2 2 2 2 2 2 1. The 24 hour period maximum and minimum solar wind speed ranged between 446 & 414 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 6, 2018- improving. HF radio wave propagation condition “trend” Jun 7, 2018- steady. HF radio wave propagation condition “trend” Jun 8 2018- steady. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +5 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 5 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S4-5 at day, 21000-21850 kHz- S0 at night and S2-4 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #79 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. #158 Issued Friday Jun 8, 2018 at 1500 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 68.9 69.3 68.7 There had been 1 day with a 2000 UTC daily solar flux index number (DSFI) less than 70. There had been 18 days in a row with a 2000 UTC daily solar flux index number (DSFI) of 70 or higher. The official daily sunspot number (DSSN) was 0. There had been 3 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 83 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at an unsettled to quiet geomagnetic condition of 3 2 1 1 1 1 1 2. The 24 hour period maximum and minimum solar wind speed ranged between 403 & 355 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 8, 2018- steady. HF radio wave propagation condition “trend” Jun 9, 2018- steady. HF radio wave propagation condition “trend” Jun 10, 2018- steady. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +5 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 5 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S4-5 at day, 21000-21850 kHz- S0 at night and S2-4 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #81 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. (((((This gentleman has a similar forecast for solar cycle 25 and the ensuing cooling of earth’s climate as I. He just used many more words to communicate it than I did. ))))) #160 Issued Sunday Jun 10, 2018 at 1400 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 68.1 66.8 68.2 There had been 3 days in a row with a 2000 UTC daily solar flux index number (DSFI) less than 70. (((((The 2000 UTC June 9, 2018 daily solar flux index (DSFI) number of 66.8 was the lowest so far as solar cycle 24 continues to progress towards solar minimum, which should occur in 2019.))))) The official daily sunspot number (DSSN) was 0. There had been 5 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 85 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 0 1 1 0 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 334 & 285 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 10, 2018- steady. HF radio wave propagation condition “trend” Jun 11, 2018- steady. HF radio wave propagation condition “trend” Jun 12, 2018- deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +5 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 5 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S4-5 at day, 21000-21850 kHz- S0 at night and S2-4 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
Thomas Giella All Messages By This Member #82 Greetings to my fellow hamateur radio and SWL radio enthusiasts around the world. Welcome to my “not for profit” daily W4HM Daily HF Radio Wave Propagation Forecast. It’s the only daily global HF radio wave propagation forecast produced on the planet. I'm a retired heliophysicist, terrestrial meteorologist/climatologist, physical oceanographer and one of the few on the planet with advanced education and forecast experience in all disciplines. In terrestrial weather forecasting I have 45 years of experience and in solar, space and geomagnetic weather forecasting 34 years. Created and disseminated by Thomas F. Giella, W4HM in Lakeland, FL, USA ? 1988-2018. If you find this daily HF radio wave propagation forecast useful to your hamateur and SWL radio activities, feel free to drop me a line and let me know that at thomasfgiella@... I enjoy hearing from likeminded fellow radio enthusiasts. Hams and SWLs that are interested in solar, space & geomagnetic weather as well as radio wave propagation are a special group of people interested in broadening their knowledge in science. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Supporting images associated with this daily HF radio wave propagation forecast can be found in my Facebook account at and in my Twitter account at Last but not least here is my new HF radio wave propagation web page where you can sign up to receive this daily HF radio wave propagation forecast via email. /g/w4hmradiowavepropagationforecast but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by Groups.io, so you have to sign up by using an existing email address and creating a password. W4HM Solar Cycle 24 Update and 25 Forecast- Short and to the point. Solar minimum may begin later this year and may last longer than any previous solar cycle in the 20th century. When solar cycle 25 finally gets underway it could be the weakest since the middle of the 19th century. Another Dalton type lesser grand solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring which it isn’t. On February 1, 2008 I forecasted that solar cycle 24 would be the smallest solar cycle in the past 100 years. That forecast verified. I also forecasted that solar cycle 25 would be almost non nonexistent. (((((This gentleman has a similar forecast for solar cycle 25 and the ensuing cooling of earth’s climate as I. He just used many more words to communicate it than I did. ))))) #161 Issued Monday Jun 11, 2018 at 1500 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 70.5 69.1 70.2 There had been 4 days in a row with a 2000 UTC daily solar flux index number (DSFI) less than 70. The 2000 UTC June 9, 2018 daily solar flux index (DSFI) number of 66.8 was the lowest so far as solar cycle 24 continues to progress towards solar minimum, which should occur in 2019. The official daily sunspot number (DSSN) was 0. There had been 6 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 86 days with an official daily sunspot number (DSSN) of 0. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 1 2 1 0 1 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 335 & 292 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 11, 2018- steady. HF radio wave propagation condition “trend” Jun 12, 2018- mild deterioration. HF radio wave propagation condition “trend” Jun 13, 2018- mild deterioration. Northern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +1 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 1 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S3-4 at day, 21000-21850 kHz- S0 at night and S1-2 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in the summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the northern hemisphere summer season the 14000- 30000 kHz frequency range closes later due to more sun light illuminating the ionosphere than in the southern hemisphere. But the maximum usable frequency (MUF) is lower than in the southern hemisphere as heating in the F2 layer of the ionosphere is higher and the layer less concentrated. Almost daily during the northern hemisphere summer season you will find that the 25600- 26100 kHz and 28000-30000 kHz frequency ranges will open via short north-south and east-west propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds form and line up favorably much longer propagation paths open up on east-west paths. And last but not least north-south propagation paths occur across the equator via trans equatorial propagation (TEP). Southern Hemisphere Radio Wave Propagation Forecast g- 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- S9 +5 to 9 at night and S1-3 at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- S9+ 5 to 9 at night and S4-7 at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- S0 at night and S4-5 at day, 21000-21850 kHz- S0 at night and S2-4 at day, 24890-24990, 25600-26100 kHz- S0 at night and S1 at day, 28000-29700 kHz- S0 at night and S0 at day. We are now firmly in summer/winter solstice type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most unbalanced across the equator during this time period. During the southern hemisphere winter season the 14000- 30000 kHz frequency range closes sooner due to less sun light illuminating the ionosphere than in the northern hemisphere. But the maximum usable frequency (MUF) is higher than in the northern hemisphere as the F2 layer of the ionosphere is lower in height and more concentrated. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio wave propagation prediction software. I wrote it beginning in the late 1980’s but I’m sorry to say that it can’t be distributed to the general public. It does outperform VOA CAP. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP software, I do check the actual band conditions at my location in the USA and tweak the forecast manually where and when necessary. I also check global HF radio wave propagation conditions via remoted radio receivers on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I look at ionsonde stations on every continent of the globe. The hamateur radio JT65A mode RF signal levels received are based on 5 watts and ? wave dipole up at 40 feet. The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ? wave dipole up at 40 feet. The hamateur radio CW mode RF signal levels received are based on 50 watts and ? wave dipole up at 40 feet. The hamateur radio SSB RF mode signal levels received are based on 100 watts and ? wave dipole up at 40 feet. The HF shortwave broadcast band AM Mode RF signal levels are based on 100,000 watts (100 kw) and a typical high gain VOA type curtain array antenna. Please keep in mind that this is a relatively simplified HF radio wave propagation forecast, so as to keep it easily understandable and applicable by the average radio enthusiast. Globally HF radio wave propagation conditions are most evenly balanced during the fall and spring equinoxes and most diametrically opposed during the summer and winter solstices. Conditions change daily, weekly, monthly, yearly and by decade, as the sun rises and sets at different times and at different angles from the ecliptic, as well as by radio wave frequency. This is due to changes in the maximum usable frequency (MUF), lowest usable frequency (LUF) and F layer critical frequency (FoF2). Also by propagation path. The D and E layers also come into play through RF radio wave signal absorption and refraction. And then there is sporadic E (Es) radio wave propagation that can really throw a wrench into the gears so to speak. Things like sporadic E (Es) radio wave propagation and lightning storm static can impact HF radio wave propagation in an unpredictable manner and mostly bad. Ongoing solar, space and geomagnetic weather goings on also impact HF radio wave propagation conditions in a negative manner. Lower high frequency (80-30 meters) propagation conditions are impacted in a negative manner not so much by variations in the maximum usable frequency (MUF) along a particular propagation path and time but rather due to geomagnetic elevated geomagnetic conditions (Kp-3-4), storms (Kp-5 & greater) that increase signal absorption via the E layer (the altitude of the radio aurora). Also increases in the lowest usable frequency (LUF) via D layer RF signal absorption due to hard x-rays, galactic cosmic waves, elevated background solar flux levels greater than B0 and energetic proton flux levels at energies greater than 10 MeV (10+0). Higher frequency (20-10 meters) propagation conditions are impacted in a negative manner by variations in the maximum usable frequency (MUF) along a particular propagation path and time due to the current sunspot number and also due to elevated geomagnetic conditions (Kp-3-4), storms of Kp-5 & greater. Also D layer RF signal absorption due to elevated (greater than B0) background solar flux levels. Also to a lesser extent elevated proton flux at energies greater than 10 MeV (10+0). GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO ACTUAL HF PROPAGATION CONDITIONS- NOTE!!! The propagation indices "interpretations" are my personal intellectual property. Therefore the radio wave propagation indices interpretations contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM, all rights reserved. Reproduction of information herein is allowed without permission in advance as long as proper credit is given. All 14 of the following indices have to occur as described below in order to see the best global high frequency radio wave propagation possible, something that happens rarely. 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best. 2.) A daily sunspot number of 150 or higher, 200 or higher best. 3.) A daily sunspot number of greater than 100 for routine stable formation of the E Valley/F Layer ducting mechanism. 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days consecutively are best. 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer than 2 for high latitude paths, 0 for several days consecutively is best. 6.) Energetic protons no greater than 10 MeV (10+0). 7.) Background x-ray flux levels greater than B1 for several days consecutively, greater than C1 best. 8.) No current STRATWARM alert. 9.) Interplanetary magnetic field (IMF) Bz with a (positive number) sign, indicates a lesser chance of high latitude path aurora absorption/unpredictable refraction or scattering of medium frequency RF signals, when the Kp is above 3. 10.) A -10 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the equatorial ring current. A positive number is best. Standard Disclaimer- Note! I use error prone RAW public domain data from the NOAA Space Environment Center, other U.S. government entities and educational institutions, to produce this daily HF radio wave propagation forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this daily HF propagation forecast that I produce from the RAW public domain data is my personal intellectual property. Therefore this daily HF radio wave propagation forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this daily HF radio wave propagation forecast, as long as you redistribute it in its entirety and give me credit for it. Also HF radio wave propagation forecasting is still an inexact science and therefore also an art. The forecasts are not official but for educational and hobby related purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.

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W4HM Daily HF Radio Wave Propagation Forecast #2018-139

W4HM Daily HF Radio Wave Propagation Forecast

#2018-139