QST de W1AW
Propagation Forecast Bulletin 14 ARLP014
From Tad Cook, K7VVV
Seattle, WA April 1, 1999
To all radio amateurs
SB PROP ARL ARLP014
ARLP014 Propagation de K7VVV
This bulletin is going out one day early because ARRL HQ is closed on Friday.
Solar activity has been in the doldrums again recently. This past week the average solar flux was over 20 points lower than the previous week, and average sunspot numbers were over 40 points lower. The average weekly sunspot number reported in this bulletin has not been this low since February 4-10 of this year, and the average solar flux hasn't been this low since June 18-24 of last year. The only bright spot has been the season, with early spring being a good time for HF propagation.
April 1 is not only the end of March, but the end of the first quarter of 1999, a time to look at some averages.
The average solar flux for March was only 126.3, much lower than the 142 average for February, 142.4 for January, and 150.1 for December. This solar cycle is supposed to peak next year at much higher levels than it is running right now, yet it seems to be in decline.
The average flux for the first quarter of 1999 is 136.7, which is very close to the 135.4 average for the last quarter of 1998 and not much higher than the 129.2 average for the third quarter of last year.
Not very encouraging, is it?
For the next few days, Thursday through Saturday, expect solar flux around 105, 110 and 110, and a planetary A index around 15, indicating unsettled to active geomagnetic conditions. After Saturday look for a rising solar flux, reaching 130 by Monday, 140 by April 8, and peaking around 150 for April 10-13. Unless some new activity appears on the sun, flux levels may be back to where they are now after April 20. Look for unsettled geomagnetic conditions around April 10-11 and active conditions around April 25.
In brief VHF news, many North American 6 meter stations were working South and Central America on March 24 and 28 with good signals. TI5KD in Costa Rica worked several African stations on 6 meters on Monday.
Sunspot Numbers for March 25 through 31 were 48, 33, 45, 65, 63, 72 and 70 with a mean of 56.6. 10.7 cm flux was 107, 103.6, 104.5, 103, 104.2, 104.7 and 102.4, with a mean of 104.2, and estimated planetary A indices were 8, 6, 4, 6, 24, 18 and 14, with a mean of 11.4.
Here are some path projections for this weekend from Dallas, Texas: