ZCZC AP52
QST de W1AW
Propagation Forecast Bulletin 52 ARLP052
From Tad Cook, K7VVV
Seattle, WA December 24, 1998
To all radio amateurs
SB PROP ARL ARLP052
ARLP052 Propagation de K7VVV
The last propagation bulletin of 1998 is going out one day early so it can be distributed before the Christmas holiday. The author wishes everyone a warm holiday greeting, and promises better HF DX for all in 1999.
Solar activity was off a bit last week, with average sunspot numbers lower by almost 55 points, and average solar flux down by only 2 points. Average solar flux for the previous ninety days was 133, and flux values were above this level on every day except Tuesday, indicating a general upward trend.
For the next few days, solar activity should be higher. The Thursday through Sunday solar flux is predicted to be 145, 148, 150 and 154, with planetary A index for each of those days at 9.
Recently we have reported optimistic news on the recovery of the Solar and Heliospheric Observatory, or SOHO project. There is a new report this week that the remaining gyro has failed, making future recovery operations when the craft is pointing away from the sun impossible. After SOHO was off for a long period earlier this year, only one of the three gyros remained working, and now that last one has failed. Currently there are no scientific operations planned until new flight software for gyroless operations is implemented. For more details, see http://sohowww.nascom.nasa.gov.
In VHF news this week, KD4ESV in Florida worked TI2ALF in Costa Rica on 6 meters, and heard K2OY, also in Florida, working HP2CWB in Panama. WA5JCI in Texas heard strong signals on 6 meters from ZF1DC in the Cayman Islands.
Sunspot Numbers for December 17 through 23 were 93, 76, 88, 98, 72, 56 and 78 with a mean of 80.1. 10.7 cm flux was 146.1, 154.7, 137.3, 134.7, 135.3, 128.8 and 139.8, with a mean of 139.5, and estimated planetary A indices were 2, 3, 7, 11, 3, 5 and 8, with a mean of 5.6.