ZCZC AP45
QST de W1AW
Propagation Forecast Bulletin 45 ARLP045
From Tad Cook, K7VVV
Seattle, WA November 6, 1998
To all radio amateurs
SB PROP ARL ARLP045
ARLP045 Propagation de K7VVV
Solar activity was up for the week, but down over the past month. Average solar flux for July through September was 114.1, 136 and 137.7, and only 117.3 for October. But conditions are definitely looking up over the past week. Average sunspot numbers jumped nearly 40 points to 84.7, and average solar flux increased about 17 points to 125.8. The really great news is that solar flux has been climbing rapidly this week. It jumped suddenly to 151.8 on Tuesday, and then on Thursday the three readings for the day at Penticton were 146.9, 152.7 and 158.6. The noon reading at 152.7 is the official number for the day.
This weekend could have some interesting conditions for the ARRL CW Sweepstakes. Solar flux is expected to remain high at 155, 150 and 150 for Friday through Monday, but the planetary A index for the same period is expected to be 12, 24 and 32. This is due to some solar flares on Wednesday and Thursday of this week. High K index numbers of four or five or higher will make it harder to pick up KL7 and VE8 multipliers in the weekend contest.
Beyond the weekend look for more unsettled to active geomagnetic conditions from November 14-21, with the worst period around November 15-17.
The high solar flux has made the upper bands interesting. The author has been operating mobile on 10, 15 and 17 meters, and has been working the world during the daily commute using low power and a simple mobile whip. 17 meters has been particularly fun, since the higher frequencies often aren't open yet on the west coast during the early morning drive to work.
Sunspot Numbers for October 29 through November 4 were 81, 81, 71, 79, 76, 81 and 124 with a mean of 84.7. 10.7 cm flux was 109.5, 111.5, 118.7, 121.4, 126.1, 151.8 and 141.4, with a mean of 125.8, and estimated planetary A indices were 8, 5, 5, 3, 5, 5 and 5, with a mean of 5.1.