I mentioned in a previous post about the horrible conditions on Sunday. On Monday, I got the following special propagation bulletin from the ARRL:
QST de W1AW
Propagation Forecast Bulletin 20 ARLP020
From Tad Cook, K7RA
Seattle, WA May 16, 2005
To all radio amateursThis is a special edition of the Propagation Forecast Bulletin.
On Friday the Thirteenth (May 13, 2005) at 1650z a tremendous
explosion near sunspot 759 blasted toward earth. The impact on the
earth’s magnetic field was felt at 0230z on May 15, producing an
extreme geomagnetic storm.I use a service from http://www.spaceweather.com called
“SpaceWeather PHONE.” I can set parameters for alerts, and the
service calls my cell phone when events occur, such as the planetary
K index rising above a set value. The service rang me up so many
times this weekend that I finally shut the phone off. I could have
gone to the web and shut it off or raised the parameters, but at the
time I just wanted to roll over and go back to sleep.On Sunday, May 15 the planetary K index reached 9. This is huge.
The middle latitude, high latitude and planetary A indexes for
Sunday were 44, 77 and 105 respectively, all very high values. The
planetary A index predicted for Monday, May 16 is 40. Solar flux is
expected to stay around 100 for Monday through Wednesday, May 16-18.If you would like to comment or have a tip, email the author at,
[email protected].For more information concerning radio propagation and an explanation
of the numbers used in this bulletin see the ARRL Technical
Information Service propagation page at,
http://www.arrl.org/tis/info/propagation.html. An archive of past
bulletins is found at, http://www.arrl.org/w1aw/prop/.
I guess Friday the 13th was an unlucky day for radio amateurs.
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