ARRL

ARRL Propagation Bulletin ARLP011 (1998)

SB PROP @ ARL $ARLP011
ARLP011 Propagation de K7VVV

ZCZC AP11
QST de W1AW
Propagation Forecast Bulletin 11  ARLP011
From Tad Cook, K7VVV
Seattle, WA  March 13, 1998
To all radio amateurs

SB PROP ARL ARLP011
ARLP011 Propagation de K7VVV

Average solar flux was down less than a point last week compared to
the previous week.  Average sunspot numbers dropped from 73.7 to
59.1  Solar flux has risen in the past few days though.  It was
101.6 on Thursday as this bulletin was written, and the flux values
forecast for this weekend are 105, 105 and 110 on Friday through
Sunday.

Solar flux is expected to decline below 100 after Sunday, then drop
to the mid nineties by next Thursday, and up around 100 again by
March 27.  Unsettled geomagnetic conditions could return around
March 17, 29 and April 6.

The most active solar region is number 8176, first observed six days
ago with 25 sunspots.  The geomagnetic field has been active
recently, with the worst days on March 10 and 11, with planetary K
indices as high as six.

We are still moving toward the spring equinox, but solar flux has
been too low for much excitement on higher frequencies.  Most 10
meter paths have been disappointing, and fans of the 28 MHz band
will probably have to wait until this fall to see much action there.

Sunspot Numbers for March 5 through 11 were 42, 54, 54, 57, 49, 75
and 83 with a mean of 59.1.  10.7 cm flux was 96.7, 91.7, 91.9,
91.2, 90, 96.3 and 100.7, with a mean of 94.1, and estimated
planetary A indices were 9, 6, 5, 2, 3, 25, and 28, with a mean of
11.1.
NNNN
/EX