ARRL

ARRL Propagation Bulletin ARLP032 (2000)

SB PROP @ ARL $ARLP032
ARLP032 Propagation de K7VVV

ZCZC AP32
QST de W1AW  
Propagation Forecast Bulletin 32  ARLP032
From Tad Cook, K7VVV
Seattle, WA  August 11, 2000
To all radio amateurs 

SB PROP ARL ARLP032
ARLP032 Propagation de K7VVV

Thanks to Carl, K9LA for writing this report last week while the
regular reporter vacationed on the Oregon coast. Your author did not
observe any solar activity while gone, other than some dramatic
sunsets.

Average sunspot count was up this week over last, although the
average solar flux remained about the same. Solar flux for the
recent short term seems to have bottomed out by the end of July, and
is currently rising. The expected near term peak is around 215 on
August 17, although last week, as reported in this bulletin, it
looked like it would be a bit higher, around 240.

The next minimum is expected around August 26-29 when flux should be
around 150. Geomagnetic conditions may be unsettled to active for
the Worked All Europe DX CW Contest this weekend, with predicted A
indices for Friday through Monday of 12, 12, 18 and 15. Predicted
solar flux for those same days is 185, 190, 195 and 200.

Jim Henderson, KF7E wrote a note awhile back pointing out what great
images are at the SOHO (Solar and Heliospheric Observatory) web
site, which is at http://sohowww.nascom.nasa.gov/ .

He particularly wanted to direct readers toward a truly astonishing
image, http://umbra.nascom.nasa.gov/eit/images/Sun_and_earth.jpg,
which appears to be a dramatic coronal mass ejection. In the picture
is an image of a tiny earth, just to put things in proper
perspective. He also would like to direct our attention to
http://sohowww.nascom.nasa.gov/data/CME/ , an archive of coronal
mass ejection images.

The SOHO satellite recorded a full coronal mass ejection on August 9
from sunspot group 9114. This is significant because it was toward
the center of the sun's visible disk, and aimed toward earth. There
was a similar second event around 0654z on August 10, although it
was reported to be slow moving. This is probably the cause of any
geomagnetic instability forecast for the next few days.

Scott Craig, WA4TTK, has updated the database for his free solar
graphing software. This program grabs data from this weekly bulletin
to update your own copy of this graphing software. You can download
it at http://edge.net/~scraig/mystuff.htm for either DOS, Windows 3,
or Windows 95-98 and beyond. Because the database has been updated,
you don't have to go through old bulletins when installing the
software to bring it up to date.

Here are some path projections for the WAE contest this weekend.
These are best guesses for good propagation to Europe from average
stations. Results will vary.

From Boston, MA, 80 meters 2300-0530z (best 0130-0430z), 40 meters
2200-0700z (best 0000-0400z), 20 meters 1830-0600z and 0730-0900z
(best 0000-0300z), 15 meters possibly 1700-2200z.

From Philadelphia, PA, 80 meters 0000-0530z (best 0130-0400z, 40
meters 2230-0700z (best 0000-0400z), 20 meters 1900-0900z (best
0000-0330z), 15 meters 1930-2100z.

From Atlanta, GA, 80 meters 0030-0600z (best 0100-0430z), 40 meters
2330-0700z (best 0130-0400z), 20 meters 2030-0700z and 0930-1030z
(best 0030-0500z), 15 meters 1530-0130z, 10 meters possibly
1230-1400z or 1630-2200z.

From Birmingham, AL, 80 meters 0030-0600z (best 0130-0230z), 40
meters 2330-0700z (best 0130-0430z), 20 meters 2030-0700z and
0930-1100z (best 0000-0600z), 15 meters 1500-0130z (best
2000-2130z), 10 meters possibly 1230-1400z and 1600-2200z.

From Dayton, OH, 80 meters 0030-0530z (best 0100-0400z), 40 meters
2300-0700z (best 0130-0400z), 20 meters 2000-0730z (best
0030-0500z), 15 meters 1700-0000z, 10 meters possibly around
1330-1400z and 1800z or 2000-2100z.

From Chicago, IL, 80 meters 0030-0530z (best around 0200z), 40
meters 2330-0700z (best 0200-0400z), 20 meters 1930-0730z (best
0130-0400z), 15 meters 1700-2300z, 10 meters possibly around 1400z.

From the center of the continental United States (in central
Kansas), 80 meters 0130-0530z (best 0230-0330z), 40 meters
0030-0630z (best 0230-0430z), 20 meters 2100-0730z (best
0200-0430z), 15 meters 1500-0100z (best 2030-2200z), 10 meters
possibly 1300-1400z and 1600-2200z.

From Salt Lake City, UT, 80 meters 0230-0430z (best at 0330z), 40
meters 0200-0600z (best 0300-0430z), 20 meters 2300-0900z (best
around 0500z), 15 meters possibly 1830-2330z.

From Dallas, TX, 80 meters 0100-0600z (best 0200-0230z), 40 meters
0000-0600z (best 0200-0430z), 20 meters 2200-0800z (best
0130-0500z), 15 meters 2000-0130z, 10 meters possibly 1130z, or
1230-1400z or 1530-0000z.

From Los Angeles, CA, 80 meters 0300-0500z, 40 meters 0230-0530z, 20
meters 0030-0900z, 15 meters possibly 1700-2300z.

From Seattle, WA, 80 meters 0330-0430z, 40 meters 0230-0600z, 20
meters 2300-1000z (best 0300-0530z), 15 meters 1500-0200z, 10 meters
possibly 1530-0100z.

Sunspot numbers for August 3 through 9 were 133, 137, 161, 174, 189,
188 and 176 with a mean of 165.4. 10.7 cm flux was 154.2, 154.2,
158.6, 166, 166.9, 170.8 and 182.2, with a mean of 154.7, and
estimated planetary A indices were 12, 18, 26, 18, 9, 9 and 7 with a
mean of 14.1.
NNNN
/EX