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[HCDX] KN4LF Daily HF/LF/MF RX Prop Outlook #2004-005A

KN4LF Daily HF/LF/MF Radio Propagation Outlook #2004-005A



http://www.kn4lf.com/kn4lf5.htm                                                                                                                                                                         http://www.hard-core-dx.com/index.php?topic=Propagation   http://dayton.akorn.net/pipermail/propagation                                                                                                                                          

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Date Format is MM/DD/YYYY
Published Sunday 12/05/2004 At 1600 UTC Valid 12/05-09/2004



During the past three days geomagnetic indices have been very quiet. Also the solar wind speed has been unusually slow at under 300 and the density also very low. As a matter of fact most of the guideline parameters necessary to see good propagation conditions have been met. The end result has been pretty good HF/MF propagation conditions, actually the best in about a month.




Here are the general guideline parameters concerning correlation of propagation indices to actual expected HF/MF propagation conditions. 

1.) Dropping indices numbers are better. 

2.) For medium frequencies a solar flux under 150, under 100 better, 70 is best for E layer multi hop. 

Keep in mind though that the 10.7 cm (2800 mhz) solar flux index is not a "reliable" gauge of ionization in our atmosphere for F layer HF frequency refractions, as the energy of photons at this frequency is to low on the order of one million times. However most are used to solar flux and sunspot number and it's a hard habit to break. A better indicator is the background x-ray flux. See #7 below. 

3.) Solar flux of at least 100 for E valley-F layer ducting mechanism. 

4.) Previous 24 hour Ap index under 10, under 7 for several days consecutively is best. 

5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for high latitude paths, 0-1 for several days consecutively is best. 

6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and no greater then (10-1) on MF broadcast band. 

7.) Background x-ray flux levels less than C1 for several days consecutively for 160/120 meters and less then B9 for MF broadcast band but A9 or less best. 

8.) No current STRATWARM alert. 

9.) IMF Bz with a (positive number) sign, indicates a lesser chance of high latitude path auroral absorption/unpredictable refraction or scattering of MF RF signals, when the Kp is above 3. 

10.) A -50 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the Equatorial Ring Current. 





On Friday 12/03/04 I predicted the chance of polar cap absorption on high latitude propagation paths due to excessive energetic protons >10 Mev (10+0) as low. 



Only to have a brief period with excessive energetic protons >10 Mev (10+0) on UTC 12/03-04/04, tied to the coronal mass ejection released by sunspot group # 10708 on Friday. 



So I'm still a little rusty at forecasting space weather after returning from my long sabbatical.



Note! From a standpoint of satellite component damage, energetic protons >10 Mev (10+0) is the threshold for warnings. 



But as far as high latitude propagation path absorption, >(10-1) creates absorption on the 530-1700 kc broadcast band and >(10+0) on 160 and 120 meters.

 



As previously forecasted, full halo CME #1 which was released in association with the M1.2 solar flare by sunspot group #10708 on 12/01/04, arrived at the ACE satellite at approximately 0700 UTC today. But as the Bz has initially turned strongly northward, geomagnetic conditions have been at worst unsettled (Kp-3) to active (KP-4).



As CME #2 arrives later today I still expect minor (Kp-5) to moderate (Kp-6) geomagnetic storming to commence. There is also still a chance for major (Kp-7) geomagnetic storming.





I see no need to update and or repeat publication of actual propagation path forecasts contained in outlook #2004-05 at this time.

 



Standard Disclaimer-
 
Note! I use "RAW" public domain data from the NOAA Space Environment Center, as well as other U.S. government organizations, to produce my "not for profit" propagation forecast outlooks. This data is gathered and made public by the U.S. Government using taxpayer $$$. However the forecast outlooks that I produce from the "RAW" public domain data, is my personal intellectual property. Therefore the propagation outlooks contained herein is copyrighted © 1988-2004 by Thomas F. Giella and the Florida Space and Atmospheric Weather Institute, all rights reserved. Reproduction of information herein is allowed as long as proper credit is given.
 
Also space weather forecasting is still an inexact science. The discussions, forecasts and outlooks are not official but for educational purposes only and are subject to human error and acts of God, therefore no guarantee or warranty implied.
 
73 & GUD DX,
Thomas F. Giella, KN4LF
Retired Space & Atmospheric Weather Forecaster
Plant City, FL, USA
Grid Square EL87WX
Lat & Long 27 58 33.6397 N 82 09 52.4052 W
kn4lf@xxxxxxxx

 

Propagation eGroup: http://lists.contesting.com/mailman/listinfo/propagation
PropNET Beacon Program: http://www.propnet.org
KN4LF Daily Solar Space Weather & Geomagnetic Data Archive: http://www.kn4lf.com/kn4lf5.htm
KN4LF HF/MF Frequency Radio Propagation Theory Notes: http://www.kn4lf.com/kn4lf8.htm
KN4LF Amateur & SWL Radio History: http://www.kn4lf.com/index.htm

 




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