ZCZC AP22
QST de W1AW
Propagation Forecast Bulletin 22 ARLP022
From Tad Cook, K7VVV
Seattle, WA May 28, 1999
To all radio amateurs
SB PROP ARL ARLP022
ARLP022 Propagation de K7VVV
Solar flux and sunspot numbers were down slightly from last week. Average flux was down less than three points, and average sunspot numbers were down about 14 points from the week previous. Geomagnetic disturbances were down also, but only by a little. The most active day was May 25, when the planetary A index was 19 and the planetary K index was as high as five.
For the CQ Worldwide WPX CW Contest this weekend, the predicted solar flux for Friday through Sunday is 155, 165 and 165, which is good. Unfortunately there was a coronal mass ejection on the sun which may cause a planetary A index of 12, 25 and 20 for those same three days. Saturday could be difficult for the contest.
Beyond the weekend, the solar flux should reach 175 by June 7 or 8, then drop to 150 around June 11, 140 by June 16, and 130 around June 21. June 14 could be bad for HF because of geomagnetic disturbances caused by coronal hole effects.
In VHF news, N4VHF in Florida worked ZF1DC on 6 meters in Cayman Islands on May 17 and KA4DON just a short distance away worked IK4GRO in Italy on 6 meters on May 22. On May 23 N0LL in Kansas worked or heard a number of stations up and down the East Coast and around the Midwest using 2 meter E-skip.
Sunspot Numbers for May 20 through 26 were 121, 128, 121, 104, 104, 130 and 152 with a mean of 122.9. 10.7 cm flux was 142.5, 140.3, 140.2, 140.7, 136.9, 143.1 and 152.6, with a mean of 142.3, and estimated planetary A indices were 10, 7, 5, 10, 11, 19 and 8, with a mean of 10.
The path projection for this week is from Cleveland, Ohio.