ZCZC AP08
QST de W1AW
Propagation Forecast Bulletin 8 ARLP008
From Tad Cook, K7VVV
Seattle, WA February 20, 1998
To all radio amateurs
SB PROP ARL ARLP008
ARLP008 Propagation de K7VVV
Solar activity was way up this week, with average solar flux increasing by almost 18 and average sunspot numbers up nearly 34 points. Solar flux was above the average of 96 for the previous 90 days on five out of seven days this week. Solar flux peaked on Sunday at 107.3. This value last topped out at 108.3 three weeks earlier. A February 14 coronal mass ejection caused disturbed conditions a few days later, resulting in planetary geomagnetic A indices of 14 and 26.
As this report was being written on Thursday evening the solar flux had dropped to 98.5. On Friday, Saturday and Sunday the flux is predicted to be 97, 95 and 95. Over the next few weeks solar flux is predicted to drift toward the mid to low eighties after March 1, then rise to the mid-nineties by the middle of March.
As daylight lengthens in the northern hemisphere, expect more openings on 15 meters during periods of high solar flux. Look for fair conditions during the ARRL International CW DX Contest this weekend, with no predicted geomagnetic conditions.
Sunspot Numbers for February 12 through 18 were 67, 62, 88, 86, 88, 85 and 64 with a mean of 77.1. 10.7 cm flux was 90.6, 94.7, 104.8, 107.3, 106.8, 104.9 and 103.3, with a mean of 101.8, and estimated planetary A indices were 8, 6, 5, 3, 3, 14, and 26, with a mean of 9.3.