ARLP037 Propagation de KT7H: September 1, 1995

Propagation Forecast Bulletin 37 ARLP037
From Tad Cook, KT7H
Seattle, WA September 1, 1995
To all radio amateurs

ARLP037 Propagation de KT7H

Solar activity was up a bit over the past week, with average Sunspot Numbers increased by about 29 points and Solar Flux up by about 7. Solar flux peaked just above 80 last week, and is now headed slowly down. Flux values should start increasing again after mid- September, reaching current levels by the end of the month.

Near the end of solar cycle 22 we are seeing very little geomagnetic activity, so conditions are stable, but HF propagation is poor. The A index, a 24 hour indicator of geomagnetic stability, was only in the double digits twice during the past week. Many days have had 3 hour K indices of zero, which is as low as it can get. The K index is a short term indicator of geomagnetic conditions.

Look for slightly active geomagnetic conditions around September 5 and 6 and again to a somewhat lesser degree around September 10 and 11. These events will be caused by recurring coronal holes, rotating back into position on the Sun.

In September we have the Fall equinox on September 23. Look for better seasonal HF conditions, although there won't be any help from solar activity.

Sunspot Numbers for August 24 through 30 were 40, 59, 63, 49, 33, 21 and 19, with a mean of 40.6. 10.7 cm flux was 77.1, 77.1, 77.3, 79.9, 81.6, 78.1 and 77.4, with a mean of 78.4.

The path projection for this week is to Turks Caicos Islands (VP5) from Tucson, Arizona, Omaha, Nebraska and Cleveland, Ohio.

From Tucson 80 meters looks good from 0100z to 1100z and 40 meters from 2300z to 1300z. 30 meters could be open around the clock on some days, but the worst time is from 0730z to 1100z and the best is from 2330z to 0500z. 20 meters should be good from 1430z to 0200z. 17 meters should be open most days from 1700z to 0000z. On some days 15 meters may open from 1900z to 2200z.

From Omaha check 80 meters from 0000z to 1100z, 40 meters from 2200z to 0600z and 40 meters again from 1100z to 1300z. 30 meters should be open from 1230z to 0400z. 20 meters should be open most days from 1600z to 0000z.

From Cleveland 80 meters should be open from 2300z to 1100z. 40 meters may be open around the clock, with the best period from 0000z to 1030z and the poorest period from 1500z to 1900z. Check 30 meters from 1030z to 1200z and again from 1400z to 0500z. 20 meters should be open from 1200z to 1430z and also from 1930z to 0200z. 17 meters should be open most days from 1430z to 0000z, with the best time from 1700z to 1800z. On some days 15 meters may open from 1700z to 2230z.