[CQ-Contest] Geomagnetic Storm still in Progress

NW7US, Tomas nw7us at hfradio.org
Tue Jul 27 10:22:02 EDT 2004


At the time of preparing this NW7US Propagation Bulletin, 1345 27 July  
2004 UTC, we are still under a major geomagnetic storm.  The Planetary K  
index is reading 8, as is the Bolder, Colorado K index.  The planetary K  
index has been at 7 or higher for the last four reporting periods (each  
period is three hours in length), or, for the last twelve hours.  The  
Interplanetary Magnetic Field (IMF) has been consistantly, and strongly,  
oriented southward, and the wind speed has been very high, caused by the  
passage of a very fast and powerful coronal hole mass ejection.  Visual  
Aurora was reported as far south as Texas, and radio Aurora has been very  
active.  DX clusters are showing radio AU as high as 222 MHz, not just in  
North America, but across Asia and Europe, as well.

The result of all of this long-duration geomagnetic storminess at such  
high levels is to wipe out HF communications.  Most of the HF band is  
experiencing severe depression of normal Maximum Usable Frequencies.   
Depressions of as high as 35 percent are happening at this time.

At the same time, radio Aurora propagation opportunity continues on 28 MHz  
and higher, up into the UHF frequencies.  If you are not on the radio, you  
will never know.  Get active, today!

These conditions, caused by the passage of a very powerful and fast  
coronal mass ejection, should subside by 28 July 2004 UTC.  However,  
conditions will continue to be rocky on 28 July and into 29 July.

I will update as conditions warrent.

73 de Tomas, NW7US (AARØJA/AAAØWA)

: Propagation Editor for CQ, CQ VHF, and Popular Communications :
: Quarterly Propagation Columnist for Monitoring Times Magazine :
: Creator of live propagation center - http://prop.hfradio.org/ :
: Member, US Army Miltary Affiliate Radio Service (MARS) AARØJA :
: 122.93W 47.67N / Brinnon, Washington USA - CN87 - CW/SSB/DIGI :
: Website, software, database design - http://newwebmakers.com/ :
: Washington State Army MARS, State Army MARS Director - AAAØWA :
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