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.
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.