ARRL

ARRL Propagation Bulletin ARLP008 (1998)

SB PROP @ ARL $ARLP008
ARLP008 Propagation de K7VVV

ZCZC AP08
QST de W1AW
Propagation Forecast Bulletin 8  ARLP008
From Tad Cook, K7VVV
Seattle, WA  February 20, 1998
To all radio amateurs

SB PROP ARL ARLP008
ARLP008 Propagation de K7VVV

Solar activity was way up this week, with average solar flux
increasing by almost 18 and average sunspot numbers up nearly 34
points.  Solar flux was above the average of 96 for the previous 90
days on five out of seven days this week.  Solar flux peaked on
Sunday at 107.3.  This value last topped out at 108.3 three weeks
earlier.  A February 14 coronal mass ejection caused disturbed
conditions a few days later, resulting in planetary geomagnetic A
indices of 14 and 26.

As this report was being written on Thursday evening the solar flux
had dropped to 98.5.  On Friday, Saturday and Sunday the flux is
predicted to be 97, 95 and 95.  Over the next few weeks solar flux
is predicted to drift toward the mid to low eighties after March 1,
then rise to the mid-nineties by the middle of March.

As daylight lengthens in the northern hemisphere, expect more
openings on 15 meters during periods of high solar flux.  Look for
fair conditions during the ARRL International CW DX Contest this
weekend, with no predicted geomagnetic conditions.

Sunspot Numbers for February 12 through 18 were 67, 62, 88, 86, 88,
85 and 64 with a mean of 77.1.  10.7 cm flux was 90.6, 94.7, 104.8,
107.3, 106.8, 104.9 and 103.3, with a mean of 101.8, and estimated
planetary A indices were 8, 6, 5, 3, 3, 14, and 26, with a mean of
9.3.
NNNN
/EX