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ARRL Propagation Bulletin ARLP009 (1999)

ARLP009 Propagation de K7VVV

QST de W1AW  
Propagation Forecast Bulletin 9  ARLP009
From Tad Cook, K7VVV
Seattle, WA  February 26, 1999
To all radio amateurs 

ARLP009 Propagation de K7VVV

Solar activity was down this week, but so were geomagnetic
disturbances after a rough start.  Last Thursday the Planetary A
index was 54, the Boulder A index was 41, and the high latitude A
index was 89.  Friday wasn't much better, but on Saturday and Sunday
geomagnetic activity was very low, with K indices at all latitudes
at zero during many periods.

Average solar flux was down about 45 points from last week to this
week, and average sunspot numbers were off about 65 points.  Solar
flux should continue to decline, with predicted flux values for this
weekend, Friday through Sunday, at 120, 118 and 115, and planetary A
indices at 8, 8 and 10.  Solar flux is expected to bottom out around
105 from March 3-5, then rise to 130 by March 8, 160 by March 10,
and peak around 200 on March 13.  After that it is expected to
decline to 120 around March 22.  This is all based on the previous
solar rotation, so new activity could increase these numbers with
little warning.  During that period geomagnetic conditions are
expected to be unsettled around March 5 and 6, more so on March 11,
and especially on March 16-18, about 28 days or one solar rotation
since the last big disturbance.

The author received a nice email from JA7SSB passing along greetings
from his JA colleagues.  He says he likes the WA4TTK solar plotting
program, and mentioned a ham radio web site he maintains at

OK1HH, a Czech propagation forecaster, also sent along some
propagation info and mentioned a site with his forecasts at

Sunspot Numbers for February 18 through 24 were 135, 122, 118, 103,
108, 38 and 56 with a mean of 97.1.  10.7 cm flux was 168.1, 164.2,
157.1, 147.2, 129.7, 127 and 119.8, with a mean of 144.7, and
estimated planetary A indices were 54, 38, 5, 5, 4, 7 and 11, with a
mean of 17.7.

Here are some path projections for this weekend from the center of
the continental United States.

To Western Europe, 80 meters looks good from 2330-0830z, 40 meters
2200-0930z, 30 meters 2000-0500z and 0930-1030z, 20 meters 1330-
2130z, 17 meters 1500-1930z, 15 meters 1630-1830z, and perhaps 12
meters around 1800z.

To South Africa, 80 meters should be open 2330-0430z, 40 meters
2330-0500z, 30 meters 2200-0530z, 20 meters 1900-0130z, 17 meters
1600-2330z, 15 meters 1430-2200z, 12 meters 1600-2000z, and perhaps
10 meters 1700-2030z.

To the Caribbean, 80 meters should work from 2330-1200z, 40 meters
2130-1300z, 30 meters around the clock, with best propagation around
0000-0500z, 20 meters 1300-0100z, 17 meters 1400-2300z, 15 meters
1500-2200z, 12 meters around 1700-1830z.

To South America, check 80 meters 0030-1000z, 40 meters 2330-1030z,
30 meters 2230-1130z, 20 meters almost always, with the worst times
around 1000-1300z and weaker signals around 1600-1900z, 17 meters
1300-0130z, 15 meters 1400-0100z, 12 meters 1500-2330z, and 10
meters 1530-2200z.

To the South Pacific, 80 meters looks good from 0530-1400z, 40
meters 0430-1430z, 30 meters 0330-1530z, 20 meters 0130-1500z and
1700-1800z, 17 meters 1700-0330z, 15 meters 1730-0300z, 12 meters
1730-0130z and 10 meters 1830-0000z.

To Japan, 80 meters should open 0800-1400z, 40 meters 0730-1430z, 30
meters 1100-1430z, 20 meters 2030-0230z, 17 meters 2200-0100z, 15
meters 2200-0000z and 12 meters perhaps from 2230-2330z. 


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