QST de W1AW
Propagation Forecast Bulletin 24 ARLP024
From Tad Cook, K7VVV
Seattle, WA June 11, 1999
To all radio amateurs
SB PROP ARL ARLP024
ARLP024 Propagation de K7VVV
Average sunspot numbers were way up this past week, rising over 38 points compared to last week. Average solar flux was up about 4 points. You can see a good general trend in rising indices at http://www.dxlc.com/solar/ or at WM7D's solar resource site at http://www.wm7d.net/hamradio/solar/.
There has been a general downward trend in solar flux and sunspot numbers since the beginning of the year, but the monthly averages have recovered. The average solar flux for December through April was 150.1, 140.6, 141.9, 126.3 and 117.2, but in May it rose to 148.4. Average sunspot numbers for the same period were 81.9, 62.4, 66.1, 69.1 and 63.9, and for May it rose to 106.3.
For this weekend, Friday through Sunday, the predicted solar flux is 165, 160 and 160. The expected planetary A index for those days is 10, 12 and 8.
Beyond this weekend the flux will probably dip down, then rise above 160 again around June 27. Recurring coronal holes will probably cause a moderate rise in geomagnetic activity this Saturday, and again around June 14 and 21.
Sunspot Numbers for June 3 through 9 were 176, 209, 233, 238, 198, 192 and 204 with a mean of 207.1. 10.7 cm flux was 173.5, 170.9, 164, 167.9, 157.7, 156.5 and 165.2, with a mean of 165.1, and estimated planetary A indices were 8, 8, 4, 4, 4, 15 and 13, with a mean of 8.
Path projections this week are from Dallas, Texas. Next week will be Southern California's turn.