ARLP043 Propagation de K7VVV:
October 23, 1998

Propagation Forecast Bulletin 43 ARLP043
From Tad Cook, K7VVV
Seattle, WA October 23, 1998
To all radio amateurs

ARLP043 Propagation de K7VVV

Solar activity was up again last week, but not by much. Average sunspot numbers increased from 95 to 113.6 and average solar flux was up from 119.7 to 125.9. The big event of the week was a major geomagnetic storm on Monday, when the planetary A index shot up to 52. The planetary K index was as high as 6 and the high latitude K index reached 7. This was all due to a coronal mass ejection on October 15.

Conditions should be fair for the CQ Worldwide DX Phone contest this weekend. There is a chance that coronal holes could disrupt geomagnetic conditions, but on Thursday night the predicted solar flux is around 115 for Friday through Sunday, and a planetary A index for the same three days of 15, 12 and 10. Beyond the weekend, the solar flux is expected to stay around 115, then rise around November 3, to peak near 125 on November 4 and 5. Look for unsettled conditions around November 3 to 6.

KB4NEW sent word about an interesting chart on the NASA Space Science News website. Go to, then click on ''Oct 19: Sunspot Activity Increases.'' An article follows which talks about Cycle 23 predictions at the Marshall Space Flight Center, and clicking on the graph will reveal a large high resolution chart showing actual sunspot numbers against a very smooth predicted graph.

W2PAT sent some interesting statistics on PSK errors when detecting data on the CHU signal on 7.355 MHz. His records show an average number of 43 errors on each day from October 12 to 18, but on October 19 the errors went up to 422, the day with the big geomagnetic storm conditions.

Sunspot Numbers for October 15 through 21 were 113, 120, 107, 136, 116, 104 and 99 with a mean of 113.6. 10.7 cm flux was 131.1, 131, 135.4, 125.9, 118.5, 121.2 and 118.3, with a mean of 125.9, and estimated planetary A indices were 6, 4, 9, 10, 52, 17 and 23, with a mean of 17.3.