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ARRL Propagation Bulletin ARLP004 (1998)

ARLP004 Propagation de K7VVV

Propagation Forecast Bulletin 4  ARLP004
From Tad Cook, K7VVV
Seattle, WA  January 23, 1998
To all radio amateurs

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

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

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.


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