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ARRL Propagation Bulletin ARLP024 (2002)

ARLP024 Propagation de K7VVV

QST de W1AW  
Propagation Forecast Bulletin 24  ARLP024
From Tad Cook, K7VVV
Seattle, WA  June 14, 2002
To all radio amateurs 

ARLP024 Propagation de K7VVV

Solar activity has been fairly low recently, or at least it seems
low compared to the rest of the long peak of this solar cycle.  On
June 13 the NOAA SESC sunspot count was 126, the lowest in nearly a
month.  Check this image of the sun from the same day, and you won't
see many sunspots facing earthward.

Now take a look at the image for May 24, when the sunspot count was
at 242, a recent peak.

A few days before that on May 20 the total area of sunspots was even
greater, over two and a half times what it was on June 13.

Between those earlier dates was a great deal of geomagnetic
activity, due to solar coronal mass ejections.  The day prior to the
May 24 image, the mid-latitude A index was 52 and the planetary A
index was 54, indicating a severe geomagnetic storm.

This week sunspot numbers and solar flux were lower.  Average daily
Sunspot numbers were down over 33 points from last week's average,
and average solar flux was down over 21 points.

No big upsets are predicted for the next few days, which is good for
participants in the All Asia DX CW Contest this weekend. Solar flux
is expected to rise over the next few days, to 135, 140 and 145 for
Friday through Sunday.  Current projection shows a peak around 185
from June 23-25.

N7QF wrote from Bountiful, Utah about his six-meter experiences in
the recent VHF contest.  John was at 9,100 feet on a mountain peak
in Northeast Utah.  He ran 90 watts into a 3 element Yagi, and
reports that the best opening was on Saturday morning from 7-9 AM
local time (1300-1500 UTC) when he ran contacts from stations in the
southwest and midwest ''like crazy, one after the other for a couple
hours.''  The temperature outside his station wagon ranged from 20-30
degrees F, but the experience was wonderful and the great openings
made it all worthwhile.  He also had minor openings to all three
west coast states, as well as VE6, VE7, Texas and Louisiana.

Sunspot numbers for June 6 through 12 were 190, 190, 181, 180, 177,
131 and 134, with a mean of 169. 10.7 cm flux was 154.5, 158.3,
155.2, 157.1, 151.6, 147.8, and 141.7, with a mean of 152.3.
Estimated planetary A indices were 10, 9, 15, 15, 16, 12, and 10,
with a mean of 12.4.


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