ZCZC AP04
QST de W1AW
Propagation Forecast Bulletin 4 ARLP004
From Tad Cook, K7VVV
Seattle, WA January 23, 1998
To all radio amateurs
SB PROP ARL ARLP004
ARLP004 Propagation de K7VVV
Solar activity was only slightly higher over the past seven days compared to last week. Average solar flux was up only about three points, but the average sunspot number was about double from the week previous. Average solar flux for the previous 90 days moved from 95 to 96 this week, but flux values were above 96 only two days out of the reporting week. This observation is consistent with the relatively flat nature of recent conditions in the current solar cycle.
Solar flux for this weekend is predicted to be around 92, with some geomagnetic instability resulting in a projected A index of around 12. This is not terrible news for the CQ Worldwide 160 meter CW Contest this weekend, but not as good as some recent conditions, where A and K indices were down near zero.
Solar flux is expected to dip soon into the high eighties, then rise above ninety again around February 3. This is all based on the previous solar rotation, so all HF operators can hope for are some new sunspot groups to liven up the bands.
Sunspot Numbers for January 15 through 21 were 46, 88, 89, 67, 88, 50 and 25 with a mean of 64.7. 10.7 cm flux was 97.8, 97.5, 95.9, 95.1, 93.5, 91.4 and 90.9, with a mean of 94.6, and estimated planetary A indices were 3, 8, 5, 9, 4, 11, and 8, with a mean of 6.9.
The ARRL DX Bulletin notes this week that FT5X/FR5HR is active from Kerguelen Islands around 0200z on 20 meters and 1400z on 17 meters. Conditions from most of the U.S. to Kerguelen don't look good at those times on those bands, but 17 meters may be possible from the East Coast. The further south one is in this hemisphere though, the better the odds. Conditions to Kerguelen from South America and the Caribbean on 20 meters should be quite good around 0200z.