ARRL

ARRL Propagation Bulletin ARLP022 (1998)

SB PROP @ ARL $ARLP022
ARLP022 Propagation de K7VVV

ZCZC AP22
QST de W1AW
Propagation Forecast Bulletin 22  ARLP022
From Tad Cook, K7VVV
Seattle, WA  May 29, 1998
To all radio amateurs

SB PROP ARL ARLP022
ARLP022 Propagation de K7VVV

Solar indices were down this week, as they have been during the past
few weeks.  The sunspot number is half what it was the previous
week, and the solar flux was down over 16 points.  So far this month
the average flux is running about the same as April and March, when
it took a jump of about 16 points over January and February.

Solar flux is expected to peak over the next two days (Friday and
Saturday) at 98, then drift to 96 on Sunday, then go below 90 after
June 7.  Flux values should drift above 90 around June 18 and to the
mid-nineties in the week prior to the end of June.

During June we will be experiencing more summer-like HF conditions,
with weaker daytime signals and higher noise due to increased
thunderstorm activity in the northern hemisphere.  With less hours
of darkness and more storms, look for poorer conditions on 160 and
80 meters.  Although 20 meters has been the best DX band around the
clock, there is a good chance that solar activity will move higher
this summer, and 15 meters could become the best daylight band for
the season.

There was a solar flare during early hours UTC on May 28, but it is
not expected to affect geomagnetic indices.  About 12 hours earlier
there was some activity that could cause a rise in geomagnetic
activity on May 30 or 31.  Look for very quiet geomagnetic
conditions around June 9-13 and possibly on June 15 and 18.

There were a couple of errors in last week's bulletin ARLP021
regarding VHF openings.  Concerning W1LP and an opening on six
meters, it was really a two meter tropo opening.  Also the W1JJM
report of EA7 and CT3 signals was for ten meters, not six.

For this week, WA5JCI in Texas reports the best tropo openings in
years, when he worked several Gulf Coast states, and then heard
Mexico on a local two meter repeater.  Also, N0JK in Kansas worked a
number of Gulf Coast and Midwest states on 2 meter tropo, and heard
KT4AL in Florida on 432 MHz.

Sunspot Numbers for May 21 through 27 were 29, 26, 47, 41, 57, 49
and 49 with a mean of 42.6.  10.7 cm flux was 89, 87.4, 90.3, 95.6,
92.3, 92.5 and 94, with a mean of 91.6, and estimated planetary A
indices were 14, 8, 13, 16, 15, 8, and 7, with a mean of 11.6.
NNNN
/EX