ARRL

ARRL Propagation Bulletin ARLP026 (1998)

SB PROP @ ARL $ARLP026
ARLP026 Propagation de K7VVV

ZCZC AP26
QST de W1AW
Propagation Forecast Bulletin 26  ARLP026
From Tad Cook, K7VVV
Seattle, WA  June 26, 1998
To all radio amateurs

SB PROP ARL ARLP026
ARLP026 Propagation de K7VVV

Solar activity was lower again last week, and geomagnetic indices
were unsettled.  The average solar flux for the previous 90 days
dropped one point from 108 to 107, and the solar flux for every day
last week was lower than those figures.  This is not a good
indicator for an upward trend.

Over the next week the solar flux is expected to rise, reaching 115
from this weekend until the following July 4 weekend.  The flux
should go below 110 again around July 10.

On Friday through Sunday, June 26 through 28 the solar flux is
forecast to be rising, at 110, 112 and 115.  Over those same days
look for unsettled conditions on Friday with a planetary A index
around 15, and then an A index of 8 over the next two days.  It
looks like fairly good conditions for this Field Day weekend, with
solar flux about 40 points higher than the 1997 Field Day.

Many readers of this bulletin use the WA4TTK Solar Data Plot Utility
by Scott Craig.  It grabs data out of this bulletin and stores it in
a database, then plots the data for you.  Users had problems
grabbing the data from the past two bulletins due to some
inadvertent changes in wording in ARLP024 and ARLP025.  Scott has
released version 3.03 which fixes this problem, and you can download
it from Scott's homepage at http://edge.net/~scraig/index.html.

Here are some path projections for the Field Day weekend.

From the East Coast to the West Coast, check 80 meters from 0230z to
1030z, peaking around 0430z to 0900z.  40 meters should be good from
0030z to 1230z, and peak from 0400z to 0930z.  20 meters should be
open around the clock, with conditions slowly getting better in the
evening until 0500z.  15 meters may open around 0300z to 0500z.

From the East Coast to the Central U.S. check 80 meters from 2300z
to 1230z, with excellent signals around 0930z.  40 meters looks good
around the clock, peaking from 0100z to 1000z.

From the West Coast to the Central U.S. 80 meters looks good from
0215z to 1230z, peaking from 0530z to 1000z.  40 meters is open all
the time, but best conditions are from 0400z to 1030z. 20 meters is
best around 2300z to 0800z and 1100z to 1530z. There may be some 15
meter openings from 0330z to 0530z.

From the Pacific Northwest to the Southeastern states, 80 meters
looks good from 0030z to 1100z, and 40 meters from 0030z to 1300z.
20 meters looks promising from 1500z to 0600z and around 1230z to
1300z.

Don't forget to check 10 meters for some sporadic E skip.

Sunspot Numbers for June 18 through 24 were 68, 67, 80, 87, 64, 59
and 64 with a mean of 69.9.  10.7 cm flux was 100.1, 101.2, 101.1,
102, 100.5, 95.7 and 105.3, with a mean of 100.8, and estimated
planetary A indices were 7, 14, 14, 15, 10, 10, and 14, with a mean
of 12.
NNNN
/EX