ARLP016 Propagation de K7VVV:
April 16, 1999

Propagation Forecast Bulletin 16 ARLP016
From Tad Cook, K7VVV
Seattle, WA April 16, 1999
To all radio amateurs

ARLP016 Propagation de K7VVV

Solar activity was up this week, but only slightly, with the average solar flux rising less than 13 points over last week. The average sunspot number was up about 30 points. More mail came this week from folks convinced that this solar cycle is not only a big disappointment now, but may continue to be. Unfortunately there is really no method of forecasting except to look at previous cycles, which tells us to expect more activity in the future. The big worry is that the predicted peak in solar activity, believed to be about a year from now, keeps getting closer, and the sunspot numbers and solar flux are not where we expect them to be.

At least geomagnetic conditions have been stable, but over the next few days that should change. Planetary A index for this Friday through Sunday is predicted at 20, 20 and 15, indicating active and unsettled geomagnetic conditions. Another predicted period of geomagnetic instability is April 25 and 26. The predicted solar flux for Friday through Sunday is 118, 115 and 112, and it is expected to remain around 105 from April 22-30.

Another peak is predicted for May 4-5 with flux values around 140. This is all based on the previous solar rotation, and could change any time new activity surfaces.

Right now at least I am hearing Scandinavia on 20 meter CW late into Thursday evening here in Seattle. The big difference between this solar cycle and previous ones is that we are not seeing the great conditions on 10 and 12 meters that we expect at one year from the solar maximum.

Sunspot Numbers for April 8 through 14 were 125, 139, 129, 103, 113, 122 and 107 with a mean of 119.7. 10.7 cm flux was 139.1, 136.2, 136.3, 130.7, 130, 129.6 and 120.2, with a mean of 131.7, and estimated planetary A indices were 9, 5, 11, 9, 7, 5 and 7, with a mean of 7.6.

The path projection for this week are from Seattle and the Pacific Northwest::