ARRL

ARRL Propagation Bulletin ARLP015 (1998)

SB PROP @ ARL $ARLP015
ARLP015 Propagation de K7VVV

ZCZC AP15
QST de W1AW
Propagation Forecast Bulletin 15  ARLP015
From Tad Cook, K7VVV
Seattle, WA  April 11, 1998
To all radio amateurs

SB PROP ARL ARLP015
ARLP015 Propagation de K7VVV

Solar activity continues it's march upward this week.  Average
solar flux for the previous 90 days rose two points to 101, and
flux values on every day this week were above this level,
indicating a good upward trend.  Average sunspot numbers were up
over 11 points for this week from the week previous, and average
solar flux was up over 15 points.

Wednesday's solar flux of 140.6 was the highest since January 2,
1994.  The previous high level in this cycle was on March 15 of
this year, at 133.

Solar flux for this weekend, Friday through Sunday, is forecast at
140, 140 and 138.  Conditions should be good for the Japan
International CW DX Contest.  Next week look for flux values to
drift back around 120 by April 22, 110 by April 27, and back to 130
by May 4.  Look for unsettled conditions around April 17.

Now that solar activity is higher, 10 meters should be opening more
often, particularly on north-south paths.  20, 17 and 15 meters
have also been opening worldwide into the evening hours as daylight
is expanded in the northern hemisphere.

Sunspot Numbers for April 2 through 8 were 67, 74, 70, 82, 82, 120
and 131 with a mean of 89.4.  10.7 cm flux was 103.4, 103.6, 110.2,
126.2, 133.4, 135.2 and 140.6, with a mean of 121.8, and estimated
planetary A indices were 4, 6, 10, 4, 4, 8, and 8, with a mean of
6.3.

NNNN
/EX