QST de W1AW
Propagation Forecast Bulletin 25 ARLP025
From Tad Cook, K7VVV
Seattle, WA June 18, 1999
To all radio amateurs
SB PROP ARL ARLP025
ARLP025 Propagation de K7VVV
Average sunspot numbers were up ten points this week, and average solar flux was down by just two points. A peek at http://www.wm7d.net/hamradio/solar/ shows how the two indices have diverged a bit, with sunspot numbers climbing faster than solar flux.
Solar flux is expected to bottom out at 150 on Friday, and then rise over the weekend to 152 and 154. Planetary A index is expected to be 8, 12 and 10 over the same three days. Solar flux should be back to 160 by June 27, and stay around 165 June 28 through July 10. This is based on the previous solar rotation, so we can always hope for new activity to push the numbers higher. But as we approach the summer solstice, even higher solar flux won't make much difference on 10 meters until the fall.
Geomagnetic indices look stable over the next few weeks, with unsettled conditions around July 5.
In VHF news, last Friday WP4O had a nice opening to the Cayman Islands and Africa on 6 meter SSB when he worked ZF1DC, EH8BPX and CT3FT, all around 2000-2200 UTC. On Wednesday of this week he worked a pile of European stations on six. N4VHF reported that on Thursday he and a number of north Florida six meter stations all worked CT3TF with good signals, and heard some weak EH8 stations. No, this is not a typo on my part. One station reported working CT3FT and the other CT3TF.
Sunspot Numbers for June 10 through 16 were 214, 211, 233, 211, 210, 240 and 201 with a mean of 217.1. 10.7 cm flux was 161.1, 164.7, 168, 167.7, 168.2, 158.5 and 152.7, with a mean of 163, and estimated planetary A indices were 7, 6, 7, 6, 4, 8 and 7, with a mean of 6.4.
Path projections for this week are from Southern California.