ARRL

ARRL Propagation Bulletin ARLP017 (1997)

SB PROP @ ARL $ARLP017
ARLP017 Propagation de KT7H

ZCZC AP17
QST de W1AW
Propagation Forecast Bulletin 17  ARLP017
From Tad Cook, KT7H
Seattle, WA  April 25, 1997
To all radio amateurs

SB PROP ARL ARLP017
ARLP017 Propagation de KT7H

Solar activity was down last week, with the daily solar flux falling
below the 74 average for the previous 90 days.  The average flux for
the week was 7 points below the previous week, and the average
sunspot number was down by about 26.  The really active geomagnetic
day was April 17 when the A index was 26, and the quiet day was May
20 when the K index dropped to zero.  Although many have called for
the end of the previous solar cycle, we still seem to be stuck in
the doldrums.

Solar flux should peak for the short term around or just above the
mid seventies at the beginning of May, and then fall possibly below
seventy in about three to four weeks from now.

Sunspot Numbers for April 17 through 23 were 29, 13, 12, 0, 0, 12
and 13 with a mean of 11.3.  10.7 cm flux was 71.7, 70.1, 69.9,
69.7, 70.1, 70.7 and 68.9, with a mean of 70.2, and estimated
planetary A indices were 26, 16, 13, 4, 16, 18, and 9, with a mean
of 14.6.

I would like to end this bulletin observing the recent death of Ed
Tilton, W1HDQ.  He wrote the propagation bulletin for many years.  I
took it over from him when he became ill during the peak of the last
solar cycle.
NNNN
/EX