ARRL

ARRL Propagation Bulletin ARLP027 (1997)

SB PROP @ ARL $ARLP027
ARLP027 Propagation de K7VVV

ZCZC AP27
QST de W1AW
Propagation Forecast Bulletin 27  ARLP027
From Tad Cook, K7VVV
Seattle, WA  July 3, 1997
To all radio amateurs

SB PROP ARL ARLP027
ARLP027 Propagation de K7VVV

Solar activity is still very low. There was some disturbance from
coronal mass ejections centered around June 27, and the planetary K
index reached up to 4 and 5.  Within a few days we were seeing K
indices of zero again, signifying stable conditions.

Over the next month no notable solar activity is expected.  Solar
flux is expected to hang around the low seventies again.  Recurring
activity could appear July 6 to 8 in the form of coronal mass
ejections, causing geomagnetic instability and a rise in the K and A
indices.

A Reuters wire service story appeared last week quoting a London
weather forecaster who observes solar activity.  The article talked
about dangers to satellite and communication systems from big solar
flares, and quoted the forecaster saying that there would be a big
disturbance between June 28 and July 3.  So far nothing has
appeared, and the news item stated that the forecaster does not
divulge his methods.

In ARLP026, I reported that the new version of the WA4TTK solar
activity graphing program is now available.  There has been a big
response, but if you don't have a copy yet, get it from Scott's web
site at http://edge.net/~scraig/.

Sunspot Numbers for June 26 through July 2 were 23, 19, 26, 24, 0, 0
and 12 with a mean of 14.9.  10.7 cm flux was 71.8, 71.7, 71.2,
70.2, 69.8, 70 and 70.1, with a mean of 70.7, and estimated
planetary A indices were 5, 16, 9, 11, 5, 4, and 4, with a mean of
7.7.
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/EX