ZCZC AP38
QST de W1AW
Propagation Forecast Bulletin 38 ARLP038
From Tad Cook, K7VVV
Seattle, WA September 19, 1997
To all radio amateurs
SB PROP ARL ARLP038
ARLP038 Propagation de K7VVV
Solar activity was off a bit this week after the fantastic rise during the recent period. The 90 day average of solar flux rose another two points this week to 79, and the flux on every day was above this running average. As of September 17 the daily flux has been above the running average continuously for 44 days.
Geomagnetic activity was mostly stable this week, with the best day on September 17. Currently as this is written on early September 19 geomagnetic conditions have been unstable and even stormy, but this should stabilize over the next few days.
Look for solar flux to dip as low as the eighties over the next few days, and then bounce back above 90 after September 25, above 100 after month's end, above 110 after October 6 and below 100 again after October 12.
We move into Fall next week. Look for better seasonal conditions, and with the higher solar activity the upper HF bands should have better propagation.
Sunspot Numbers for September 11 through 17 were 98, 97, 85, 74, 61, 62 and 52 with a mean of 75.6. 10.7 cm flux was 108.6, 109, 107.6, 102.5, 98, 95.4 and 93.1, with a mean of 102, and estimated planetary A indices were 9, 15, 10, 12, 16, 9, and 8, with a mean of 11.3.