QST de W1AW
Propagation Forecast Bulletin 9 ARLP009
From Tad Cook, K7VVV
Seattle, WA March 3, 2000
To all radio amateurs
SB PROP ARL ARLP009
ARLP009 Propagation de K7VVV
Solar activity really took a big jump over the past week. Average solar flux was up almost 57 points from the previous week, and average sunspot numbers were up nearly 66 points. Solar flux peaked on Wednesday, March 1, with a reading of 232.8. Geomagnetic indices were also higher. The peak day for the planetary A index was Thursday, February 24 when it was 26. Planetary K indices were mostly 4 for the day, but reached 5 at one point.
Last week's bulletin spoke of a predicted near term peak in solar flux around Wednesday, but about 25 points lower.
The short term forecast for this week shows a declining solar flux for Friday, March 3 through Tuesday, March 7 of 210, 210, 205, 195 and 190. Solar flux is expected to bottom-out near 145 around March 16 or 17, then rise above 200 again after March 23.
Unfortunately, the outlook for the ARRL International DX Phone Contest this weekend is not positive, at least in terms of geomagnetic indices. The predicted planetary A index for Friday through Tuesday is 12, 28, 25, 20 and 15. It is a shame that the predicted A index for Saturday and Sunday is 28 and 25, but it sometimes comes with increased solar activity. Beyond the weekend geomagnetic conditions should stay quiet until March 22 and 23, then quiet down again until March 31 and April 1. 210.4, 214.8, 227.3, 218.8, 219 and 232.8, with a mean of 216.5, and estimated planetary A indices were 26, 18, 12, 10, 12, 6 and 19, with a mean of 14.7.
Are you in Texas, and planning on participating in this weekend's contest? Then this path projection is for you. This is for Saturday, March 4, from Dallas.
Contesters this weekend can always hope, and monitor WWV for updated K indices. If the K index, which is updated every three hours, is three or lower, that is a good sign. If you want the last solar bulletin broadcast on WWV and want to use a telephone instead, dial 303-497-3235.
News from http://www.spaceweather.com/ this week spoke of two intense solar flares erupting on March 2, and another piece at http://science.nasa.gov/headlines/y2000/ast02mar_1m.htm was a story about a polar substorm caused by solar wind, which it described as a ''gale of energetic particles from the sun.'' The cause of some of the recent activity is described in an article at http://spacescience.com/headlines/y2000/ast29feb_1.htm from NASA Space Science News.
Sunspot numbers for February 24 through March 1 were 181, 202, 193, 201, 186, 211 and 247 with a mean of 203. 10.7 cm flux was 192.2