ZCZC AP11
QST de W1AW
Propagation Forecast Bulletin 11 ARLP011
From Tad Cook, KT7H
Seattle, WA March 14, 1997
To all radio amateurs
SB PROP ARL ARLP011
ARLP011 Propagation de KT7H
Sunspot activity was up last week, but solar flux was about the same, average values increasing by a little over one point. Geomagnetic activity was lower.
Over the next few weeks solar flux is expected to stay right in the mid seventies. Geomagnetic activity is expected to increase due to recurring coronal holes around March 26 and 27. This is an echo of the rise in A index that we saw on February 28.
Next week will be the Spring equinox. Expect improved conditions as periods of daylight equalize between the southern and northern hemispheres. Due to continued low flux values, night propagation on 20 meters will still be a problem, as will daytime propagation on 10 and 15 meters. After dark the best bands will be 30 and 40 meters. Best propagation on 20 meters will continue to be in the morning after sunrise toward the east, and in the late afternoon and early evening toward the west.
Sunspot Numbers for March 6 through 12 were 11, 12, 26, 26, 17, 15 and 21 with a mean of 18.3. 10.7 cm flux was 75.4, 74.1, 74.7, 75.1, 74.7, 74.3 and 74.3, with a mean of 74.7. Estimated planetary A indices for the same period were 8, 8, 5, 3, 3, 4, and 12, with a mean of 6.1.