ARRL

ARRL Propagation Bulletin ARLP022 (1997)

SB PROP @ ARL $ARLP022
ARLP022 Propagation de K7VVV

ZCZC AP22
QST de W1AW
Propagation Forecast Bulletin 22  ARLP022
From Tad Cook, K7VVV
Seattle, WA  May 30, 1997
To all radio amateurs

SB PROP ARL ARLP022
ARLP022 Propagation de K7VVV

Solar activity declined slightly from the recent peak, which was
centered around May 21.  Propagation has been very good, with
worldwide openings on 20 meters into the late evening here on the
West coast.  Last week the solar flux was above the 90 day average
of 74 on every day.  A new region of sunspots appeared on May 23 and
again on May 27.  In the previous week one new region appeared on
May 16, two on May 17, two on May 19, and one on May 21.  At last
conditions seem to be pulling out of the doldrums.

Geomagnetic conditions were upset on May 27 when the planetary A
index was 21.  The Planetary K index jumped to a very high value of
6 at 0300z, indicating a severe disturbance, but it then dropped
back to 2 by 0900z, a very stable quiet value.

Based on recent conditions, the next solar rotation is expected to
produce a decline in solar flux to the low seventies until June 11,
when the flux should rise back toward 80.  Of course this assumes no
new activity, and new activity from the new solar cycle is what we
hope for.

Sunspot Numbers for May 22 through 28 were 66, 58, 52, 50, 38, 43
and 25 with a mean of 47.4.  10.7 cm flux was 81, 76.2, 76.9, 78,
80, 78.3 and 77.4, with a mean of 78.3, and estimated planetary A
indices were 4, 3, 6, 5, 8, 21, and 6, with a mean of 7.6.

(This bulletin is still written by Tad Cook, who recently changed
his callsign from KT7H to K7VVV.)
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/EX