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ARRL Propagation Bulletin ARLP033 (1998)

ARLP033 Propagation de K7VVV

Propagation Forecast Bulletin 33  ARLP033
From Tad Cook, K7VVV
Seattle, WA  August 14, 1998
To all radio amateurs

ARLP033 Propagation de K7VVV

Solar activity was up again last week in a big way.  Average sunspot
numbers were up by 42 points and average solar flux was up over 32
points.  The highest solar flux was on August 9 when it was 154.1.
The last time the flux was this high was in early 1993.

Over the next few days, Friday through Sunday, look for solar flux
to decline to 140, 135, and 130.  Solar flux should go under 120
around August 20 and down to 110 around August 22, then increase to
over 150 again after the beginning of September.  The planetary A
index was very high at 69 on August 12, and we should see high A
index values indicating geomagnetic disturbances around August 19
and 20.

There is more good news concerning the SOHO satellite, which is used
to observe the sun.  The satellite has now recovered to the point
that it is sending out some data, such as temperature readings.

With solar flux over 150 and the season changing soon to Fall,
strong 10 meter openings cannot be too far away.  15 meters should
be stronger as well, now that the solar cycle seems to be moving up

Sunspot Numbers for August 6 through 12 were 122, 127, 121, 155,
136, 144 and 137 with a mean of 134.6.  10.7 cm flux was 138.3, 145,
146.8, 154.1, 149.2, 150.1 and 147, with a mean of 147.2, and
estimated planetary A indices were 69, 28, 12, 4, 14, 9, and 10,
with a mean of 20.9.