ZCZC AP18
QST de W1AW
Propagation Forecast Bulletin 18 ARLP018
From Tad Cook, KT7H
Seattle, WA May 2, 1997
To all radio amateurs
SB PROP ARL ARLP018
ARLP018 Propagation de KT7H
Solar activity was up a tiny bit last week, but the daily solar flux was still below the previous 90 day average of 74 on each day. Solar flux peaked slightly at 73.1 on April 27.
April 26 to 29 had very quiet geomagnetic indices, with an A index of 4 each day and many periods with a K index of zero, the best there is for HF conditions.
The projection for the rest of May indicates more flat conditions, but of course this is based only upon the previous solar rotation. Since there has been no significant activity over the past month, then there are no known really active regions to rotate into view.
Sunspot Numbers for April 24 through 30 were 13, 12, 32, 17, 17, 12 and 0 with a mean of 14.7. 10.7 cm flux was 69.8, 68.7, 70.9, 73.1, 72.4, 71.9 and 72.6, with a mean of 71.3. Estimated planetary A indices were 15, 7, 4, 4, 4, 4, and 11, with a mean of 49.