ZCZC AP43
QST de W1AW
Propagation Forecast Bulletin 43 ARLP043
From Tad Cook, K7VVV
Seattle, WA October 24, 1997
To all radio amateurs
SB PROP ARL ARLP043
ARLP043 Propagation de K7VVV
Unfortunately, solar activity is continuing its downward drift, which was unexpected following the recent hopeful signs from solar cycle 23. Average solar flux was off about one point last week referenced to the previous week, and sunspot numbers are down as well. Solar flux on the last four days of this week has been below the average for the previous ninety days, which is never a good sign.
The only consolation has been stable geomagnetic conditions with low K and A indices, but this may change, since on October 21 there was a coronal mass ejection from the Sun. This might produce some unstable conditions for the CQ World Wide DX SSB contest this weekend, but forecasters are not certain.
Based on the 27.5 day solar rotation, solar flux is expected to drift around the low eighties over the next few weeks. On the day that this bulletin was written, the solar flux even dipped just below 80. The solar flux has not been this low in about two months.
Sunspot Numbers for October 16 through 22 were 45, 52, 45, 37, 25, 27 and 13 with a mean of 34.9. 10.7 cm flux was 87.5, 88.2, 86.6, 85.3, 82.8, 85 and 80.7, with a mean of 85.2, and estimated planetary A indices were 3, 5, 3, 3, 6, 4, and 5, with a mean of 4.1.