ARLP048 Propagation de K7VVV:
November 27, 1997

Propagation Forecast Bulletin 48 ARLP048
From Tad Cook, K7VVV
Seattle, WA November 27, 1997
To all radio amateurs

SB PROP ARL ARLP048 ARLP048 Propagation de K7VVV

Over the past week we experienced mostly good conditions, with the exception of last weekend. The Planetary A Index, an indicator of geomagnetic instability, rose to 45 and 60, and the Planetary K index rose as high as seven on both days. This indicated a major to severe geomagnetic storm, which began after 0900 UTC on November 22 and continued until about 1500 UTC the next day.

Solar flux rose over the week. The average solar flux for the previous 90 days rose two more points to 93, and the daily solar flux values were above the 90 day average on all days except last Thursday. Average solar flux for the week was up about six points over the previous week.

For the contest weekend, expect excellent conditions. Barring some unforeseen solar flare, the geomagnetic indices are expected to remain low. The 10.7 cm solar flux should keep rising. The three daily flux measurements for Wednesday at Penticton were 106.3, 108.1 and 109.2, and over the next few days the best guess places the flux around 110 on Thursday and 115 on Friday and Saturday.

Solar activity may begin falling off after December 2, with flux values dropping below 100 by December 8 and back up over 100 by December 22. Judging from activity during the previous solar rotation, disturbed periods will probably center around December 3 and December 19 and 20.

Sunspot Numbers for November 20 through 26 were 57, 52, 62, 70, 61, 58 and 43 with a mean of 57.6. 10.7 cm flux was 88.7, 95.9, 100.2, 99.8, 103.3, 102.1 and 108.1, with a mean of 99.7, and estimated planetary A indices were 2, 2, 45, 60, 7, 3, and 2, with a mean of 17.3.

Here are some path projections for the contest weekend.

From the Eastern USA:

From the Western USA: