ARRL

ARRL Propagation Bulletin ARLP046 (1998)

SB PROP @ ARL $ARLP046
ARLP046 Propagation de K7VVV

ZCZC AP46
QST de W1AW  
Propagation Forecast Bulletin 46  ARLP046
From Tad Cook, K7VVV
Seattle, WA  November 13, 1998
To all radio amateurs 

SB PROP ARL ARLP046
ARLP046 Propagation de K7VVV

Solar activity was much higher over the past week.  Average sunspot
numbers jumped almost 34 points to 118.6 and average solar flux was
up about 25 points to 151.2.  The average for solar flux for the 90
days prior to this week was 131.3, and flux values were above this
level on every day of this week, which is a good sign of an upward
trend.

The most active day was Monday, when the solar flux was above 160.
Unfortunately for HF operators this was also the second of two days
of geomagnetic storms, with Sunday's planetary A index at 68 and
Monday's at 78.  The high latitude A index was 130 on Monday.  It
was a weekend of uneven conditions for the ARRL Sweepstakes.

These conditions which meant poor propagation on HF produced some
interesting effects on VHF.  W1JJM in Rhode Island reported working
CX8BE in Uruguay on six meters, and W1LP in Massachusetts heard a
beacon from Malawi on six as well.  W1LP also reported a whole list
of stations around North America worked via aurora on two meter CW.

For this weekend solar activity is expected to retreat a little,
with the solar flux on Friday through Sunday forecast at 140, 140
and 138.  Planetary A index over the same three days is predicted to
be 15, 20 and 10.  Solar flux is expected to dip below 130 after
November 18, and bottom out around 120 from November 20 through 24.

Flux values should rise above 130 after November 27, and peak below
150 around December 1 and 2.  Geomagnetic conditions are expected to
be unstable until November 18.  This is all based on activity during
the previous solar rotation, and new active areas on the sun could
appear at any time.

Next week look out for the big Leonid meteor storm on November 17.
This should be a peak year in the Leonid's 33 year cycle, and the
best viewing should be over Northern Asia.

Sunspot Numbers for November 5 through November 11 were 137, 142,
144, 137, 107, 81 and 82 with a mean of 118.6.  10.7 cm flux was
152.7, 140.9, 148.5, 152.7, 162.4, 153.8 and 147.1, with a mean of
151.2, and estimated planetary A indices were 9, 22, 25, 68, 78, 6
and 4, with a mean of 30.3.
NNNN
/EX