ARRL

ARRL Propagation Bulletin ARLP011 (1999)

SB PROP @ ARL $ARLP011
ARLP011 Propagation de K7VVV

ZCZC AP11
QST de W1AW  
Propagation Forecast Bulletin 11  ARLP011
From Tad Cook, K7VVV
Seattle, WA  March 12, 1999
To all radio amateurs 

SB PROP ARL ARLP011
ARLP011 Propagation de K7VVV

Average solar flux was about the same this week compared to last,
rising less than 4 points.  Average sunspot numbers were identical
over the same two periods.  Solar activity rose until the end of
last week, and fell this week, providing the close averages.

Geomagnetic activity has been way up, causing aurora and lots of
interesting VHF propagation.  The most active day in the past week
was Tuesday, when the planetary A index reached 31, and planetary K
indices as high as 6.  VE6XT reported that Tuesday this was the
ninth consecutive night with aurora in Western Canada.  On that same
day a number of stations reported good DX openings on 6 meters, with
many of South American stations worked by U.S. hams.  AJ4Y reported
that South Americans on 6 meters, including many LU stations, were
sounding like 10 meters in a DX contest.

On March 9 and 10 ZL3TTC noted that he worked an XE1 and a pile of
JA stations on 6 meters.  Signals were very strong.

In other news, several people sent copies of a wire service story
about spaces scientists announcing that an S shaped structure on the
face of the sun can be used to predict coronal mass ejections.
These eruptions cause the geomagnetic upsets of recent days.  The S
shaped image can be detected with x-ray satellites, and this allows
predictions of geomagnetic storms to be made several days earlier
than current methods.

Someone wanted to know the latest forecast telling when this solar
cycle should peak.  The last forecast shows a peak in smoothed solar
flux around this time next year at around 210.

Joe Reisert, W1JR writes that he thinks 1999 has been a good year so
far for band conditions.  He keeps a yearly count of DXCC countries
worked, and in a typical year the number is 275.  In 1998 he worked
289 countries, and in the first two months of this year his count
was 240.  This is all with 100 watts.

For this weekend, expect more geomagnetic disturbances, with a
planetary A index for Friday through Sunday of 12, 15 and 23.  This
activity is expected to continue through the next week, with A
indices finally dropping to the single digits around March 20.
Expect more disturbed activity on March 28 through April 3.  Solar
flux for this weekend is predicted at 140, 140 and 135, through
Sunday.

Sunspot Numbers for March 4 through 10 were 144, 135, 136, 93, 107,
89 and 88 with a mean of 113.1.  10.7 cm flux was 144.1, 127.5,
114.4, 110, 126.9, 127.1 and 135.4, with a mean of 126.5, and
estimated planetary A indices were 23, 18, 11, 25, 10, 23 and 31,
with a mean of 20.1.

Here are some path projections for this weekend from Atlanta,
Georgia:

To Western Europe, 80 meters 2300-0730z, 40 meters 2200-0900z, 30
meters 1930-0900z and 1100-1200z, 20 meters 1200-2300z, 17 meters
1330-2100z, 15 meters 1500-2000z, 12 meters 1700-1830z, and possibly
10 meters 1700-1900z.

To South Africa, 80 meters 2300-0445z, 40 meters 2230-0545z, 30
meters 2130-0600z, 20 meters 1930-0730z, 17 meters 1700-0200z, 15
meters 1130-0100z, 12 meters 1200-2300z, 10 meters 1300-2130z.

To the Caribbean, 80 meters 2230-1145z, 40 meters, 30 meters and 20
meters all hours, best signals 0000-1000z, weakest 1630-1800z, 17
meters 1130-0200z, 15 meters 1200- 0100z, 12 meters 1300-2300z, 10
meters 1400-2100z.

To South America, 80 meters 2330-1000z, 40 meters 2300-1030z, 30
meters 2200-1200z, 20 meters all hours, best 0000-0900z, weakest
1600-1700z, 17 meters 1200-0200z, 15 meters 1230-0200z, 12 meters
1330-2230z, 10 meters 1400-2200z.

To Hawaii, 80 meters 0400-1245z, 40 meters 0300-1330z, 30 meters
0130-1500z, 20 meters all hours, strongest around 0400z and 1300z,
17 meters 1630-0300z, 15 meters 1700- 0130z, 12 meters 1730-0000z,
10 meters 1830-2100z.

To the South Pacific, 80 meters 0530-1230z, 40 meters 0500-1300z, 30
meters 0400- 1400z, 20 meters 0130-1430z, 17 meters 1700-0330z and
1300-1430z, 15 meters around 1330z and 1700-0230z, 12 meters
1730-0130z, 10 meters 1730-2330z.

To Australia, 80 meters 0730-1230z, 40 meters 0730-1300z, 30 meters
0630-1330z, 20 meters 0430-1500z, 17 meters 0230-0700z, 15 meters
0000-0300z, 12 meters 2000-0200z, 10 meters 2130-0100z.

To Japan, 80 meters 0830-1200z, 40 meters 0800-1230z, 30 meters
0630-1400z, 20 meters 1300- 0330z, 17 meters 2030-0230z, 15 meters
2030-0130z, 12 meters 2130-0000z, 10 meters around 2200z.

To Central Asia, 80 meters 0000-0100z, 40 meters 2300-0130z, 30
meters 2130-0300z, 20 meters 1200-0230z, 17 meters 1300-2200z, 15
meters 1400-1630z.
NNNN
/EX