ARRL

ARRL Propagation Bulletin ARLP049 (1995)

SB PROP @ ARL $ARLP049
ARLP049 Propagation de KT7H

ZCZC AP18
QST de W1AW
Propagation Forecast Bulletin 49  ARLP049
From Tad Cook, KT7H
Seattle, WA  November 25, 1995
To all radio amateurs

SB PROP ARL ARLP049
ARLP049 Propagation de KT7H

Average sunspot numbers for the past week were about double the
week before, but solar flux was slightly lower.  While we expect
the two major indicators of solar activity to track together, they
often don't.

Solar flux is a measurement of 2800 MHz energy from the Sun, which
seems to correlate with ionization of the ionosphere.  Sunspot
numbers relate to the size and number of visible sunspots.  One
example of the two not tracking exactly is the forecast for the end
of this solar cycle and the beginning of the next.  Solar flux is
currently expected to reach minimum between January and February of
1997, while the minimum for sunspot numbers is predicted for April
through June of 1996.  Part of this may be due to the fact that the
solar flux has been tracked for fewer cycles than the sunspot
number, so the amount of data going into the projection is
different.

Over the next few weeks solar activity is expected to stay low,
with solar flux possibly peaking slightly in the mid to high
seventies around December 6.  Disturbed conditions from a weakening
coronal hole are predicted for November 27 through 30.  Look for
very stable conditions from December 7 through 9 and again after
December 16.

Sunspot Numbers for November 16 through 22 were 49, 47, 61, 15, 15,
11 and 13, with a mean of 30.1.  10.7 cm flux was 75.9, 75.1, 75.1,
74, 73.2, 72.8 and 73, with a mean of 74.2.

The path projection for the CQ Worldwide CW Contest this weekend is
from the center of the United States to Europe, East Asia, Africa,
South America, Central America and the South Pacific.

To Europe, check 80 meters from 2230z to 0830z, 40 meters from
2130z to 0000z and 0530z to 0930z.  20 meters should be open from
1500z to 1630z.

To East Asia 80 meters should be good from 0730z to 1400z, and 40
meters from 0630z to 1530z, with weaker signals from 1200z to
1230z.  20 meters looks good from 2130z to 2230z.  15 meters might
be open around 2200z.

To Africa 80 meters looks good from 2300z to 0300z, 40 meters from
2230z to 0000z and 20 meters from 1500z to 2030z.  15 meters may
have an opening centered around 1800z.

To South America 80 meters should be open from 2330z to 0930z,
40 meters from 2230z to 1000z, 20 meters from 1430z to 2230z and
15 meters from 1630z to 1900z.  10 meters may be open some days
from 1830z to 2000z.

To Central America check 80 meters from 2300z to 1230z, 40 meters
from 2030z to 0030z and again around 0700z to 1600z.  20 meters
should be good from 1600z to 2100z, and 15 meters may be open some
days from 1800z to 2030z.

To the South Pacific check 80 meters from 0930z to 1330z, 40 meters
from 0930z to 1400z and 20 meters from 1530z to 1800z.  Check 15
meters around 2100z to 2230z.  On some days 10 meters could open
around 2100z to 2200z.
NNNN
/EX