[SFDXA] W4HM Daily HF Radio Wave Propagation Forecast #2018-68

Fri Mar 9 13:42:30 EST 2018

> #68 Issued Friday March 9, 2018 at 1500 UTC
> 
> Important Solar, Space & Geomagnetic Weather Indices-
> 
> The daily solar flux index numbers (DSFI) were 67.4 66.6 66.7
> 
> There had been 18 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 7 days in a row with a daily sunspot number (DSSN) of 0.
> 
> In 2018 there had been 34 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 1 1 2 1 0 0 1 0.
> 
> The 24 hour period maximum and minimum solar wind speed ranged between 353 & 340 km/s.
> 
> Global Daily HF Radio Wave Propagation Forecast-
> 
> HF radio wave propagation condition trend March 9, 2018- deteriorating
> 
> HF radio wave propagation condition trend March 10, 2018- steady state
> 
> Steady state means that HF radio wave propagation conditions are not improving or degraded.
> 
> Northern Hemisphere Radio Wave Propagation Forecast g-
> 
> 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- 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 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- 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 ½ wave dipole up at 40 feet.
> 
> The hamateur radio PSK31 mode RF signal levels received are based on 25 watts and ½ wave dipole up at 40 feet.
> 
> The hamateur radio CW mode RF signal levels received are based on 50 watts and ½ wave dipole up at 40 feet.
> 
> The hamateur radio SSB RF mode signal levels received are based on 100 watts and ½ 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.
> 
> _______________________________________________
> Spaceweather mailing list
> Spaceweather at contesting.com
> http://lists.contesting.com/mailman/listinfo/spaceweather