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ARRL Propagation Bulletin ARLP007 (1998)

ARLP007 Propagation de K7VVV

Propagation Forecast Bulletin 7  ARLP007
From Tad Cook, K7VVV
Seattle, WA  February 13, 1998
To all radio amateurs

ARLP007 Propagation de K7VVV

Solar activity continued very low last week, with the solar flux
below the ninety day average of 96 on every day.  Average solar flux
for the week was down about six points from the previous week's
average.  Geomagnetic conditions were mostly quiet until February 11
and 12, when the planetary K index went as high as four and the
high-latitude K index went to six.  This was probably due to a small
coronal hole in the southwest quadrant of the solar disk.

The recent 27 day projection by the NOAA Space Environment Center
forecasted continued solar flux values in the low to mid-eighties,
rising to 90 around February 22 and 23.  But it is now evident that
a new active region has rotated into view.  Solar flux jumped from
86.2 to 90.6 from Wednesday to Thursday, and for Friday through
Sunday the projected solar flux is around 94.  Given the progress of
this young solar cycle compared to previous ones, we can only hope
that shortly we will see a jump in solar activity.

Cary Oler of Solar Terrestrial Dispatch (on the Web at predicts a surge in solar
activity over the next few months, with a vigorous and energetic
upswing in solar indices corresponding to the beginning of
accelerated sunspot growth.  He thinks we may see solar flux values
around 120 in the next two or three months.

Conditions should be good for the RTTY contest this weekend.  With
higher solar flux look for more daylight openings on 15 meters.

Sunspot Numbers for February 5 through 11 were 40, 41, 27, 37, 34,
62 and 63 with a mean of 43.4.  10.7 cm flux was 85.5, 84.2, 83.1,
83.6, 83.7, 83.7 and 86.2, with a mean of 84.3, and estimated
planetary A indices were 3, 3, 3, 7, 8, 8, and 13, with a mean of


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