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ARRL Propagation Bulletin ARLP003 (1999)

ARLP003 Propagation de K7VVV

QST de W1AW  
Propagation Forecast Bulletin 3  ARLP003
From Tad Cook, K7VVV
Seattle, WA  January 15, 1999
To all radio amateurs 

ARLP003 Propagation de K7VVV

Solar activity was down over the past week.  Average sunspot numbers
were off 26 points and average solar flux was down nearly 40 points
when compared to the previous week.  We are now in the middle of the
28th month of solar cycle 23, and for the rest of this month
activity should be up.

Solar flux bottomed out at 110.3 on last Sunday, but this weekend
the predicted solar flux, Friday through Sunday, is 150, 160 and
170.  Planetary A index for those three days is predicted to be 12,
9 and 9.  Look for solar flux values to stay above 150 almost until
the end of this month.

The last two days have had fairly active geomagnetic periods.  This
was probably due to a disappearing solar filament on January 9.

Scott Craig reported a couple of minor bugs in his solar plotting
program, and the fix is in version 3.05 on his web page at  One bug involves starting with
very small data files, and the other is with taking data from these
bulletins via Netscape.

ZL3TIC reported lots of activity on 6 meters on January 11 and 12,
with many JA and VK calls worked.  With the geomagnetic activity the
past two days some North American hams reported working many 6 meter
stations around the continent via aurora.  N0VSB in Colorado worked
a long list of Pacific Northwest 6 meter stations on Thursday.

Sunspot Numbers for January 7 through 13 were 125, 99, 70, 62, 46,
66 and 77 with a mean of 77.9.  10.7 cm flux was 115.1, 115.5,
114.8, 110.3, 111.9, 112.8 and 118.6, with a mean of 114.1, and
estimated planetary A indices were 6, 14, 8, 4, 4, 6 and 28, with a
mean of 10.


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