QST de W1AW
Propagation Forecast Bulletin 12 ARLP012
From Tad Cook, K7VVV
Seattle, WA March 19, 1999
To all radio amateurs
SB PROP ARL ARLP012
ARLP012 Propagation de K7VVV
Solar activity was up slightly this week. Although average sunspot numbers were about the same, average solar flux was up about 12 points over last week. Expect solar activity to go lower in the near future. For this weekend, Friday though Sunday, flux values are expected at 145, 135 and 130, and Planetary A index should be 10, 8 and 7.
Beyond the weekend look for solar flux to drop to around 125 next week, and then begin to rise around the end of the month. Watch out for recurring geomagnetic disturbances around March 28, and a slowly rising solar flux to reach 150 around April 10.
Jim Secan of Northwest Research Associates sent along a nice URL for a web page he put up which shows predicted solar flux and planetary A index over 30 days. This is plotted against the previous 27 day rotation. You can see it at http://www.nwra.com/nwra/spawx/30df.html. Be sure to check out other interesting pages in the Space Weather section of that website.
In VHF news, on March 10 from 2130-2150z, WP4O in Puerto Rico heard faint 6 meter CW signals from ZL2KT. Four days later on Sunday he reported working a string of 6 and 2 meter stations in Uruguay and Argentina. On Saturday W1LP/MM in the Caribbean worked ZL2KT on 6 meters. WB8XX in Ohio worked several Argentinean stations on 6 meters that same weekend, as did a number of other North American stations. On Wednesday of this week, WA5IYX in San Antonio worked HK3YH in Columbia on 6 meter SSB.
Sunspot Numbers for March 11 through 17 were 95, 98, 107, 131, 126, 134 and 131 with a mean of 117.4. 10.7 cm flux was 137, 140.3, 144.4, 150.4, 150.1, 155.7 and 154.5, with a mean of 147.5, and estimated planetary A indices were 13, 10, 7, 13, 16, 4 and 5, with a mean of 9.7.
Here are some path projections for this weekend from Cleveland, Ohio: