
SB PROP @ ARL $ARLP043
ARLP043 Propagation de KT7H
 
ZCZC AP57
QST de W1AW  
Propagation Forecast Bulletin 43  ARLP043
From Tad Cook, KT7H
Seattle, WA  October 21, 1994
To all radio amateurs 
 
SB PROP ARL ARLP043
ARLP043 Propagation de KT7H
 
Solar activity was up this week, and the K and A indices were quite
low.  Tuesday and Wednesday had many three hour periods when the K
index was zero, which means stable conditions with low absorption.
Coupled with solar flux over 90, we have had better conditions
compared with what we have experienced over recent weeks.
 
This will change however, because of a recent solar flare.  A
disturbance generated by this flare is expected to hit this weekend,
on October 22 or 23, which should be reflected in higher A and K
indices.  Check WWV for updates.  Every three hours there is a new K
index, and anything above three means degraded conditions with
higher absorption.  Since the K index is not linear, each change of
one point is very significant.  A K index of 4 is disturbed, and 5
is truly awful.
 
Another disturbance is expected at the end of the month, due to a
recurring coronal hole.  Look for the worst around October 30 and
31, with poor conditions probably lasting through the first few days
of November.  The solar flux should decline down to around 80 around
November 5 and 6, and then rise back to 90 before the middle of the
month.
 
Sunspot Numbers for October 13 through 19 were 69, 88, 98, 83, 68,
78 and 93, with a mean of 73.  10.7 cm flux was 93.1, 92.6, 92.7,
91.7, 91.6, 90.5 and 90.7, with a mean of 91.8.
 
The path projection for this week is from Portland, Oregon to
Pitcairn Island.
 
80 meters looks good from 0300z to 1330z, and 40 meters from 0230z
to 1400z.  Check 30 meters from 0130z to 1500z.  20 meters should be
open from 1500z to 1800z and again from 2300z to 0330z.  There may
be openings between those times, but with weaker signals.  17 meters
looks good from 1600z to 0200z, and 15 meters from 1700z to 0030z.
12 meters should be open from 1900z to 2300z.  10 meters should be
open on many days from 2000z to 2200z.
NNNN
/EX
