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Monster Media 1993 #2
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1993-06-13
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SB PROP @ ARRL $ARLP023
ARLP023 Propagation DE KT7H
QST DE W1AW
Propagation Forecast Bulletin 23 ARLP023
From Tad Cook, KT7H
Seattle, WA June 11, 1993
To All Radio Amateurs
Solar flux dropped this past week, and geomagnetic disturbances
were up. Coronal holes were the probable cause of upsets on June 4
and 5, which resulted in A indices of 37 for both days.
Then on June 7 a major flare appeared, one that was well placed to
cause maximum terrestrial havoc. Slow-moving particles took several
days to arrive, but spawned a major storm on June 10, along with
predictions of aurora visible across the northern United States.
Solar flux is expected to drop further to around 80 on June 18 and
19, which could signal a new low in activity for this side of the
current solar cycle. A moving average graph of solar flux over the
previous 90 days shows activity falling steadily.
The flux should rise to 125 around June 28, followed by a possible
geomagnetic disturbance from recurring coronal holes around June 30.
Note that right now is a peak period for E-skip. Check 10 and
6 meters for this interesting propagation mode.
Sunspot Numbers from June 3 through June 9 were 138, 119, 104, 110,
89, 63 and 62, with a mean of 97.9. 10.7 cm flux was 136.4, 129.9,
133.8, 127.5, 112.3, 112.3 and 115.4, with a mean of 123.9.
The path projection for this week is from Dallas, Texas to
Yugoslavia.
80 meters should be open from 0130z to 0330z, peaking from 0200 to
0300z. 40 meters should be open from 0030z to 0530z, peaking from
0200z to 0330z. 30 meters should be open from 2300z to 0700z, with
the best times from 0100z to 0400z. 20 meters should be open from
2000z to 0630z, peaking around 0000z to 0100z and again from 0330z
to 0530z. 17 meters is not a sure bet, but the best time is from
2030z to 2200z. Due to low solar activity, 10, 12 and 15 meters do
not look good over this path.
/EX