SB PROP @ ARRL $ARLP021
ARLP021 Propagation DE KT7H
QST DE W1AW
Propagation Forecast Bulletin 21  ARLP021
From Tad Cook, KT7H
Seattle, WA  May 28, 1993
To All Radio Amateurs

Solar activity was very low again last week.  The solar flux stayed
below 100 for most of the period, which is part of the gradual trend
downward as we head toward the minimum of the current solar cycle.

The positive side was that geomagnetic conditions were extremely
quiet.  The A index was actually between zero and two all week,
which is almost unheard of.  Those numbers would be good even if
they were K indices.  The K index was zero or one for most periods.

Solar flux is starting to head back up, but should show a slow
modest rise to only 110 before mid-June, when it will then drop back
down below 100 around June 21.  Geomagnetic conditions should stay
quiet throughout the month, but there is a possibility of a
disturbance over the weekend during the WPX CW Contest.

Twenty meters looks like the best all around HF band, with more
openings during the evening hours as we shift toward Summer
conditions.  Lower frequency communications should be more of a
problem due to seasonal increases in atmospheric noise.

Sunspot Numbers from May 20 through 26 were 48, 34, 22, 13, 38, 55
and 88, with a mean of 42.6.  10.7 cm flux was 91.1, 91, 91.8, 94.9,
98.4, 99.8 and 107.5, with a mean of 96.4.

The path projection for this week is also to Spratly Island as it
was last week, but this time from the West Coast of the United
States, centered on San Francisco.

75 and 80 meters should be good from 1030z to 1330z, with the best
conditions around 1200z.  40 meters should be open from 1000z to
1430z, but best from 1130z to 1300z.  30 meters should be open from
0930z to 1530z, peaking from 1030z to 1400z.  20 meters should be
open from 0800z to 1700z, with best bets from 0930z to 1530z.  The
best time for 17 meters looks like 0630z to 0800z, but other
possible openings may be from 1400z to 1830z.  10, 12 and 15 meters
do not look very promising, although 15 meters may have some
openings on the West Coast end from around sunset until 0830z.
/EX