ARRL

ARRL Propagation Bulletin ARLP016 (1999)

SB PROP @ ARL $ARLP016
ARLP016 Propagation de K7VVV

ZCZC AP16
QST de W1AW  
Propagation Forecast Bulletin 16  ARLP016
From Tad Cook, K7VVV
Seattle, WA  April 16, 1999
To all radio amateurs 

SB PROP ARL ARLP016
ARLP016 Propagation de K7VVV

Solar activity was up this week, but only slightly, with the average
solar flux rising less than 13 points over last week.  The average
sunspot number was up about 30 points.  More mail came this week
from folks convinced that this solar cycle is not only a big
disappointment now, but may continue to be.  Unfortunately there is
really no method of forecasting except to look at previous cycles,
which tells us to expect more activity in the future.  The big worry
is that the predicted peak in solar activity, believed to be about a
year from now, keeps getting closer, and the sunspot numbers and
solar flux are not where we expect them to be.

At least geomagnetic conditions have been stable, but over the next
few days that should change.  Planetary A index for this Friday
through Sunday is predicted at 20, 20 and 15, indicating active and
unsettled geomagnetic conditions.  Another predicted period of
geomagnetic instability is April 25 and 26.  The predicted solar
flux for Friday through Sunday is 118, 115 and 112, and it is
expected to remain around 105 from April 22-30.

Another peak is predicted for May 4-5 with flux values around 140.
This is all based on the previous solar rotation, and could change
any time new activity surfaces.

Right now at least I am hearing Scandinavia on 20 meter CW late into
Thursday evening here in Seattle.  The big difference between this
solar cycle and previous ones is that we are not seeing the great
conditions on 10 and 12 meters that we expect at one year from the
solar maximum.

Sunspot Numbers for April 8 through 14 were 125, 139, 129, 103, 113,
122 and 107 with a mean of 119.7.  10.7 cm flux was 139.1, 136.2,
136.3, 130.7, 130, 129.6 and 120.2, with a mean of 131.7, and
estimated planetary A indices were 9, 5, 11, 9, 7, 5 and 7, with a
mean of 7.6.

The path projections for this week are from the Seattle and the
Pacific Northwest:

To Western Europe, 80 meters 0230-0530z, 40 meters 0130-0700z, 30
meters 2330-0230z and 0430-0800z, 20 meters 1500-0000z.

To Eastern Europe, 40 meters 0245-0400z, 30 meters 0230-0630z, 20
meters 1430-2130z and 0230-0630z, 17 meters around 1830z.

To Southern Africa, 80 meters 0230-0400z, 40 meters 0200-0430z, 30
meters 0100-0500z, 20 meters 2130-0200z, 17 meters 1630-0100z.

To the Caribbean, 80 meters 0200-1030z, 40 meters 0100-1130z, 30
meters 2300-0830z and around 1030z and again around 1200z, 20 meters
around 1200z and again 1430-0600z, 17 meters around 1430z and
1900-0430z,  15 meters 1800-0130z.

To South America, 80 meters 0230-1030z, 40 meters 0200-1030z, 30
meters 0030-0900z and 1030-1130z, 20 meters 2230-0730z and around
1230z, 17 meters 1400-0600z, 15 meters 1530-0130z.

To Hawaii, 80 meters 0430-1430z, 40 meters 0300-1600z, 30 meters
2330-1030z and 1230- 1930z, 20 meters 1530-0900z, 17 meters
1700-0630z,  15 meters 2030-2330z.

To the South Pacific, 80 meters 0530-1400z, 40 meters 0430-1500z, 30
meters 0400- 1600z, 20 meters 0030-1000z, 1330-1530z and 1700-1930z,
17 meters 1700-0830z, 15 meters 1730-0630z, 12 meters 2030-0000z.

To Australia, 80 meters 0730-1430z, 40 meters 0700-1430z, 30 meters
0600-1600z, 20 meters 0430-1000z and 1330-1600z, 17 meters
0230-0900z,  15 meters 2030-0730z, 12 meters 2130-0030z.

To Japan, 80 meters 0830-1400z, 40 meters 0800-1530z, 30 meters
0630-1030z and 1330- 1630z, 20 meters 2000-0830z, 17 meters
2000-0500z.

To Central Asia, 40 meters around 1330z, 30 meters 1200-1530z, 20
meters 1400-2000z, 17 meters 0030-0130z.
NNNN
/EX