开云体育

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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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 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. #179 Issued Friday June 29, 2018 at 1530 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 70.2 69.5 70.2 There had been 1 day with a 2000 UTC daily solar flux index number (DSFI) less than 70. There had been 16 days in a row with a 2000 UTC daily solar flux index number (DSFI) greater than 70. The official daily sunspot number (DSSN) was 0. There had been 2 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 89 days with an official daily sunspot number (DSSN) of 0. There was no earth facing (geo effective) sunspot groups. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet geomagnetic condition of 2 1 1 1 2 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 510 & 437 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 29, 2018- steady. HF radio wave propagation condition “trend” Jun 30, 2018- minor deterioration. HF radio wave propagation condition “trend” Jul 1, 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.

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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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 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. #178 Issued Thursday June 28, 2018 at 1530 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 71.7 70.0 70.3 There had been 16 days in a row with a 2000 UTC daily solar flux index number (DSFI) greater than 70. 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) greater than 0. In 2018 there had been 88 days with an official daily sunspot number (DSSN) of 0. There were no earth facing (geo effective) sunspot groups. The 24 hour period 3 hour interval planetary K index (Kp) had been at an unsettled to quiet geomagnetic condition of 1 2 1 1 2 1 1 3. The 24 hour period maximum and minimum solar wind speed ranged between 599 & 464 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 28, 2018- improving. HF radio wave propagation condition “trend” Jun 29, 2018- steady. HF radio wave propagation condition “trend” Jun 30, 2018- minor deterioration. 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.

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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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.

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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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. https://wattsupwiththat.com/2018/02/forecast-for-solar-cycle-25 ))))) #159 Issued Saturday Jun 9, 2018 at 1430 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 68.0 68.2 68.3 There had been 2 days in a row with a 2000 UTC daily solar flux index number (DSFI) less than 70. The official daily sunspot number (DSSN) was 0. There had been 4 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 84 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 0 2 1 0 0 0. The 24 hour period maximum and minimum solar wind speed ranged between 361 & 321 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 9, 2018- steady. HF radio wave propagation condition “trend” Jun 10, 2018- steady. HF radio wave propagation condition “trend” Jun 11, 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.

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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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. #157 Issued Thursday Jun 7, 2018 at 1400 UTC Important Solar, Space & Geomagnetic Weather Indices- Solar activity was very low. The daily solar flux index numbers (DSFI) were 71.5 71.1 70.8 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 2 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 82 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 1 2 4 2. The 24 hour period maximum and minimum solar wind speed ranged between 462 & 367 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 7, 2018- steady. HF radio wave propagation condition “trend” Jun 8, 2018- steady. HF radio wave propagation condition “trend” Jun 9 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.

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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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. #154 Issued Monday Jun 4, 2018 at 1415 UTC Solar activity is very low. Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 74.0 73.6 72.9 There had been 13 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 16. There had been 14 days in a row with a daily sunspot number (DSSN) of greater than 0. But it looks like the daily sunspot number (DSSN) will fall back to 0 in the next 24 hours. Decaying sunspot group #12712 was located near N15W63 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 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 unsettled to quiet geomagnetic condition of 3 2 1 2 3 2 2 2. The 24 hour period maximum and minimum solar wind speed ranged between 709 & 557 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” Jun 4, 2018- steady. HF radio wave propagation condition “trend” Jun 5, 2018- improving. HF radio wave propagation condition “trend” Jun 6, 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.

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 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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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. #138 Issued Saturday May 19, 2018 at 1445 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 68.9 69.4 68.7 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 5 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 78 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 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 430 & 350 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 19, 2018- steady. HF radio wave propagation condition “trend” May 20, 2018- steady. HF radio wave propagation condition “trend” May 21, 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 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.

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 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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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. (((((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 going it could be the weakest since the middle of the 19th century. Another Dalton type grand solar grand 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.))))) #131 Issued Saturday May 12, 2018 at 1615 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 70.5 70.3 70.4 There had been 10 days in a row with a 2000 UTC daily solar flux index number (DSFI) below 70. We had 1 day with a 2000 UTC daily solar flux index number (DSFI) above 70. The official daily sunspot number (DSSN) was 11. There had been 8 days in a row with a daily sunspot number (DSSN) greater than 0. Sunspot group #12708 had weakened into a spotless plage. Sunspot group #12709 was located near N05E25 with a simple alpha magnetic signature capable of releasing a very, very small in size A class solar flare and an isolated very small in size B class solar flare. In 2018 there had been 73 days with a 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 2 3 3 2 2 2 3 3. The 24 hour period maximum and minimum solar wind speed ranged between 503 & 427 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 12, 2018- improving. HF radio wave propagation condition “trend” May 13, 2018- improving. HF radio wave propagation condition “trend” May 14, 2018- improving. Northern Hemisphere Radio Wave Propagation Forecast b- 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). 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. Southern Hemisphere Radio Wave Propagation Forecast b- 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. 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 4-7 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. This HF Radio wave propagation forecast is produced based on the SIGINT_CAP MF/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.

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 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 https://www.facebook.com/thomasfranklingiellaw4hm and in my Twitter account at https://twitter.com/GiellaW4hm 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. (((((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 going it could be the weakest since the middle of the 19th century. Another Dalton type grand solar grand 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.))))) #130 Issued Friday May 11, 2018 at 1200 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 69.9 69.6 74.4 There had been 10 days in a row with a 2000 UTC daily solar flux index number (DSFI) below 70. The official daily sunspot number (DSSN) was 11. There had been 7 days in a row with a daily sunspot number (DSSN) greater than 0. Sunspot group #12708 was located near S10W13 with a simple alpha magnetic signature capable of releasing a very, very small in size A class solar flare and an isolated very small in size B class solar flare. Sunspot group #12709 was located near N05E52 with a simple alpha magnetic signature capable of releasing a very, very small in size A class solar flare and an isolated very small in size B class solar flare. In 2018 there had been 73 days with a 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 3 3 3 2 3 1 2. The 24 hour period maximum and minimum solar wind speed ranged between 583 &451 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition “trend” May 11, 2018- improving. HF radio wave propagation condition “trend” May 12, 2018- improving. HF radio wave propagation condition “trend” May 13, 2018- improving. Northern Hemisphere Radio Wave Propagation Forecast b- 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). 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. Southern Hemisphere Radio Wave Propagation Forecast b- 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. 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. 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.

On Thursday May 3, 2018 the daily solar flux index numbers (DSFI) were 67.3 66.5 66.9 The 66.5 reading is the lowest so far in the solar cycle 24 down slide towards solar minimum. At solar minimum the daily solar flux number stays in the low to mid 60’s range for years at a time. 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 going it could be the weakest since the middle of the 19th century. Another Dalton type solar minimum may occur with a corresponding cooling of earth’s climate. This would negate anthropogenic climate change if it were occurring but 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. 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 solar cycle 25 forecast. This data is gathered and made public by the U.S. Government using taxpayer $$$ (including mine). However this solar cycle 25 forecast that I have produced from the RAW public domain data is my personal intellectual property. Therefore this solar cycle 25 forecast contained herein is copyrighted ? 1988-2018 by Thomas F. Giella, W4HM. Feel free without prior permission to redistribute this solar cycle 25 forecast, as long as you redistribute it in its entirety and give me credit for it. Solar cycle 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. 73 & GUD DX, Thomas F. Giella, W4HM Lakeland, FL, USA /g/w4hmradiowavepropagationforecast https://www.facebook.com/thomasfranklingiellaw4hm

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 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 space weather 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. 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 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. #112 Issued Monday April 23, 2018 at 1500 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 76.1 75.7 74.8 There had been 5 days in a row with a 2000 UTC daily solar flux index number (DSFI) greater than 70. The official daily sunspot number (DSSN) was 20. There had been 4 days in a row with a daily sunspot number (DSSN) greater than 0. In 2018 there had been 67 days with a daily sunspot number (DSSN) of 0. Sunspot group #12706 was located near N03E22 with a relatively simple beta magnetic signature capable of releasing a very small B class solar flare and an isolated small in size C class solar flare. Sunspot group #12707 was located near S10E08 with a simple alpha magnetic signature capable of releasing a very small A class solar flare and an isolated very small in size B class solar flare. The 24 hour period 3 hour interval planetary K index (Kp) had been at a quiet to geomagnetic condition of 2 2 2 1 2 1 1 2. The 24 hour period maximum and minimum solar wind speed ranged between 481 & 415 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition trend April 23, 2018- improving. HF radio wave propagation condition trend April 24, 2018- steady. HF radio wave propagation condition trend April 25, 2018- steady. Northern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 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. Southern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 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. 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.

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 heliophysicist, terrestrial meteorologist/climatologist and one of the few on the planet with advanced education & 44 years of forecasting experience in both disciplines. 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 other 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 at my new web page of /g/w4hmradiowavepropagationforecast 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. #93 Issued Tuesday April 3, 2018 at 1500 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 68.3 68.4 68.0 There had been 14 days in a row with a 2000 UTC daily solar flux index number (DSFI) below 70. The official daily sunspot number (DSSN) was 0. There had been 2 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 54 days with a 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 1 0 1 1 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 449 & 369 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition trend April 3, 2018- steady state HF radio wave propagation condition trend April 4, 2018- steady state Steady state means that HF radio wave propagation conditions are not improving or deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- very good at night and poor to fair at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- very good at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- very poor at night and good at day, 21000-21850 kHz- very poor at night and fair to good at day, 24890-24990, 25600-26100 kHz- very poor at night and fair at day, 28000-29700 kHz- very poor at night and poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 Southern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- very good at night and poor to fair at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- very good at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- very poor at night and good at day, 21000-21850 kHz- very poor at night and fair to good at day, 24890-24990, 25600-26100 kHz- very poor at night and fair at day, 28000-29700 kHz- very poor at night and poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 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. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP, 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 around on every continent of the globe and tweak the forecast manually if and when necessary. 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). 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. 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.

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 heliophysicist, terrestrial meteorologist/climatologist and one of the few on the planet with advanced education & 44 years of forecasting experience in both disciplines. 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 other 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 https://www.facebook.com/thomasfranklingiellaw4hm and at my new web page at /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. And last but not least I also post solar, space and geomagnetic weather goings on and some images in my Twitter account at https://twitter.com/GiellaW4hm #90 Issued Saturday March 31, 2018 at 1400 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 68.4 68.8 68.7 There had been 11 days in a row with a 2000 UTC daily solar flux index number (DSFI) below 70. The official daily sunspot number (DSSN) was 11. On Friday March 30, 2018 a newly risen sunspot group #12703 was located near S09E61 with a simple alpha magnetic signature capable of producing very small B class solar flares. It remains to be seen how long it lasts. There had been 1 day in a row with a daily sunspot number (DSSN) of greater than 0. In 2018 there had been 52 days with a 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 2 1 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 464 & 356 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition trend March 31, 2018- steady state HF radio wave propagation condition trend April 1, 2018- steady state Steady state means that HF radio wave propagation conditions are not improving or deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- very good at night and poor to fair at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- very good at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- very poor at night and good at day, 21000-21850 kHz- very poor at night and fair to good at day, 24890-24990, 25600-26100 kHz- very poor at night and fair at day, 28000-29700 kHz- very poor at night and poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 Southern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- very good at night and poor to fair at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- very good at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- very poor at night and good at day, 21000-21850 kHz- very poor at night and fair to good at day, 24890-24990, 25600-26100 kHz- very poor at night and fair at day, 28000-29700 kHz- very poor at night and poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 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. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP, 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 around on every continent of the globe and tweak the forecast manually if and when necessary. 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). 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. 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.

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 heliophysicist, terrestrial meteorologist/climatologist and one of the few on the planet with advanced education & 44 years of forecasting experience in both disciplines. 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 other 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 https://www.facebook.com/thomasfranklingiellaw4hm and at my new web page at /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. And last but not least I also post solar, space and geomagnetic weather goings on and some images in my Twitter account at https://twitter.com/GiellaW4hm #89 Issued Thursday March 30, 2018 at 1400 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 68.5 69.0 68.6 There had been 10 days in a row with a 2000 UTC daily solar flux index number (DSFI) below 70. The official daily sunspot number (DSSN) was 0. But this Friday March 30, 2018 a newly numbered sunspot group is rising around the east limb of the sun located near S09E68 with a simple alpha magnetic signature. It remains to be seen how long it lasts. There had been 11 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 52 days with a 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 1 2 1 1 1 1. The 24 hour period maximum and minimum solar wind speed ranged between 450 & 342 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition trend March 30, 2018- steady state HF radio wave propagation condition trend March 31, 2018- deteriorating Steady state means that HF radio wave propagation conditions are not improving or deteriorating. Northern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- very good at night and poor to fair at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- very good at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- very poor at night and good at day, 21000-21850 kHz- very poor at night and fair to good at day, 24890-24990, 25600-26100 kHz- very poor at night and fair at day, 28000-29700 kHz- very poor at night and poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 Southern Hemisphere Radio Wave Propagation Forecast g- We are now in the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- very good at night and poor to fair at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- very good at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- very poor at night and good at day, 21000-21850 kHz- very poor at night and fair to good at day, 24890-24990, 25600-26100 kHz- very poor at night and fair at day, 28000-29700 kHz- very poor at night and poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 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. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP, 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 around on every continent of the globe and tweak the forecast manually if and when necessary. 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). 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. 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.

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 heliophysicist, terrestrial meteorologist/climatologist and one of the few on the planet with advanced education & 44 years of forecasting experience in both disciplines. 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 other 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 https://www.facebook.com/thomasfranklingiellaw4hm and at http://lists.contesting.com/mailman/listinfo/spaceweather but without supporting images. It's a NO SPAM voluntary "opt" in email type group hosted by contesting on line (COL), so you have to sign up by using an existing email address and creating a password. And last but not least I also post solar, space and geomagnetic weather goings on and some images in my Twitter account at https://twitter.com/GiellaW4hm #80 Issued Wednesday March 21, 2018 at 1430 UTC Important Solar, Space & Geomagnetic Weather Indices- The daily solar flux index numbers (DSFI) were 69.0 68.8 69.3 There had been 1 day in a row with a 2000 UTC daily solar flux index number (DSFI) below 70. The official daily sunspot number (DSSN) was 0. There had been 2 days in a row with a daily sunspot number (DSSN) of 0. In 2018 there had been 43 days with a 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 3 0 0 1 1 2 1. The 24 hour period maximum and minimum solar wind speed ranged between 463 & 347 km/s. Global Daily HF Radio Wave Propagation Forecast- HF radio wave propagation condition trend March 21, 2018- steady state HF radio wave propagation condition trend March 22, 2018- deteriorating Steady state means that HF radio wave propagation conditions are not improving or deteriorating. Northern Hemisphere Radio Wave Propagation Forecast b- We are now entering the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- fair to good at night and poor at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- fair at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- poor at night and fair at day, 21000-21850 kHz- very poor at night and fair at day, 24890-24990, 25600-26100 kHz- very poor at night and poor at day, 28000-29700 kHz- very poor at night and very poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 Southern Hemisphere Radio Wave Propagation Forecast b- We are now entering the fall/spring equinox type of HF radio wave propagation conditions. Globally HF radio wave propagation conditions are most evenly balanced across the equator during the fall and spring equinox. 3150-3400, 3500-4100, 4750-5050, 5700-6300 kHz- fair to good at night and poor at day, 6900-7800, 9200-9995, 10000-10150, 11500-12200 kHz- fair at night and fair at day, 13570-13850, 14000-14350, 15005-15900, 17450-17950, 18068-18168 kHz- poor at night and fair at day, 21000-21850 kHz- very poor at night and fair at day, 24890-24990, 25600-26100 kHz- very poor at night and poor at day, 28000-29700 kHz- very poor at night and very poor at day. Excellent- S9+10 or > Very Good- S9 +1-9 Good- S8-9 Fair- S4-7 Poor- S1-3 Very Poor- S0 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. And though this HF radio wave propagation forecast is produced based on the SIGINT_CAP, 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 around on every continent of the globe and tweak the forecast manually if and when necessary. And last but not least I check data from ionsonde's scattered around the planet. 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). 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 storms (Kp-5 & >) 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 geomagnetic storms of Kp-5 & >. Also D layer RF signal absorption due to elevated (>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. 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.