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ARRL Propagation Bulletin ARLP013 (2003)

ARLP013 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 13  ARLP013
From Tad Cook, K7RA
Seattle, WA  March 28, 2003
To all radio amateurs 

ARLP013 Propagation de K7RA

Solar flux and sunspot numbers declined again this week. Average
daily solar flux was down over 31 points to 100.6, and average daily
sunspot numbers were down nearly 30 points to 62.4. Solar flux was
lowest on Saturday, March 22 at 89. Solar flux has not been this low
since 1998 when it was 89 on May 21 and 87.4 the following day.

Geomagnetic conditions were still active this week but finally
settled down after March 23. Currently on Thursday the earth is
again in a solar wind stream from a coronal hole. The best guess is
for unsettled geomagnetic activity over the next few days, but no
severe storm. The predicted planetary A index for Friday through
Monday is 15, 12, 12 and 15.

A few days ago the sun was almost devoid of spots, but more have now
rotated into view. Predicted solar flux for Friday through Monday is
150, 155, 155 and 150. Unless new activity emerges, based upon the
current solar rotation solar flux values below 100 may return by
mid-April. Propagation relative to recent conditions should be
fairly good for the CQ World Wide SSB WPX Contest this weekend.

Jon, N0JK of Wichita Kansas reported good 6-meter conditions while
geomagnetic indices were again active today. He reports that Diego,
HC8/LU8ADX on San Cristobal Island in the Galapagos was working U.S.
stations coast to coast around 2015-2130z. Diego peaked at S-9 at
Jon's location, and Jon worked him at 2048z running 10 watts or less
into a dipole.

A month ago during another period of geomagnetic activity Jon
submitted a report that the HC8GR beacon on Galapagos was loud at
his QTH, and K2RTH/4 heard the LU9EHF beacon from Miami. Readers can
submit reports of interesting propagation via email to

Tomas Hood, NW7US has developed some interesting methods for
delivering propagation data. Go to his web site at where you can sign up for email alerts,
propagation data delivered to an RSS headline reader program, or WAP
enabled wireless device.

Sunspot numbers for March 20 through 26 were 45, 40, 40, 43, 64, 89,
and 116, with a mean of 62.4. 10.7 cm flux was 97.4, 91, 89, 93,
97.8, 108.8, and 127.2, with a mean of 100.6. Estimated planetary A
indices were 21, 29, 16, 24, 10, 6, and 8, with a mean of 16.3.


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