QST de W1AW
Propagation Forecast Bulletin 46 ARLP046
From Tad Cook, K7VVV
Seattle, WA November 8, 2002
To all radio amateurs
SB PROP ARL ARLP046
ARLP046 Propagation de K7VVV
Sunspot numbers and solar flux increased last week, when the average daily sunspot number rose nearly 31 points and the solar flux was up by nearly 11. Geomagnetic indices have been quite active of late, although this week was quieter than last. Generally HF operators appreciate A indices of 10 or lower, but November 1 was the only day in the past two weeks that the Planetary A index was ever as low as 10.
Lately our planet has been inside a constant solar wind from a coronal hole. Over the past week conditions haven't been so stormy that they would produce lower latitude auroras like they did back on October 24 and 25.
A huge sunspot (number 180) has been squarely earth-directed in the center of the visible solar disk for the past couple of days, and the daily sunspot number from Monday through Thursday has risen from 166 to 175, 234 and 259. This sunspot presents a threat of solar flares. The predicted planetary A index for Friday through Monday is 10, 10, 20 and 20. Solar flux is expected to remain fairly high over the next few days.
A year ago this bulletin reported that the sunspot numbers were a small amount lower than this week (less than 4 points) and the solar flux was about 60 points higher. The latest Preliminary Report and Forecast of Solar Geophysical Data shows that smoothed solar flux should be about 44 points lower a year from now, and the latest prediction for the next solar minimum is around September 2006 through April 2007 for solar flux and centered right around December 2006 to January 2007 for smoothed sunspot number.
Here are monthly averages for solar flux and sunspot numbers for this year. From January through October, 2002 the average daily solar flux for each month was 189, 194.5, 154.3, 144.4, 146, 183.5, 191, 206.4, and 153.9. Average daily solar flux for the same months was 227.3, 205, 179.2, 141.4, 148.7, 174.4, 183.9, 175.8 and 167.
This weekend is the Japan International DX Phone Contest. The object is for non-JA stations to contact Japanese stations. To work Japan on 80 meters, try just after local sunset in Japan (around 0748z) to your local sunrise. For 40 meters, conditions should be good about an hour earlier than the 80 meter opening until an hour after your local sunrise. For 20, 15 and 10 meters, check these times:
Sunspot numbers for October 31 through November 6 were 134, 169, 177, 217, 166, 175, and 234, with a mean of 181.7. 10.7 cm flux was 170.2, 162.2, 164.6, 169.2, 177.4, 183.1, and 184.5, with a mean of 173. Estimated planetary A indices were 18, 10, 21, 27, 21, 19, and 19, with a mean of 19.3.