ZCZC AP34
QST de W1AW
Propagation Forecast Bulletin 34 ARLP034
From Tad Cook, K7VVV
Seattle, WA August 20, 1999
To all radio amateurs
SB PROP ARL ARLP034
ARLP034 Propagation de K7VVV
Solar flux and sunspot numbers were down again this week. Average sunspot numbers were down almost 55 points and average solar flux was off by over 17 points, when compared to the previous week. Geomagnetic conditions were quite stormy over the past few days, with an A index of almost thirty over several days this week. Conditions should settle down over the next few days, with planetary A indices of 20, 15 and 10 over Friday through Sunday. Solar flux has actually been rising this week, and over the weekend it should rise to 140, 145 and 150. Expect continued rising solar flux to hit 180 around August 24, peaking around 190, August 26-29. Predicted unsettled geomagnetic days are August 26-28, September 2-5, and September 11-13.
Sunspot numbers for August 12 through 18 were 100, 82, 79, 87, 71, 67 and 69 with a mean of 79.3. 10.7 cm flux was 123.1, 126.5, 128.1, 131.1, 131.1, 141 and 130.7, with a mean of 130.2, and estimated planetary A indices were 10, 11, 5, 15, 29, 27 and 26, with a mean of 17.6.
The path projections for this week are from Salt Lake City, Utah.