ZCZC AP50
QST de W1AW
Propagation Forecast Bulletin 50 ARLP050
From Tad Cook, K7VVV
Seattle, WA December 2, 2002
To all radio amateurs
SB PROP ARL ARLP050
ARLP050 Propagation de K7VVV
This is a short after-holiday catch-up bulletin to bring us up-to-date on solar flux, sunspot and planetary A index numbers. These data couldn't be covered in last week's early bulletin.
From the previous week, mean daily sunspot numbers dropped over 24 points and daily solar flux was down nearly 37 points. Average planetary A index was about double, from 11.3 to 23. The numbers run through last Wednesday, and geomagnetic indices have continued to run unsettled to active since then. In four days we should have an update for next weekend's ARRL 160 meter contest. For that event contesters will want quiet geomagnetic conditions and low A indices, preferably in the low single digits.
Over the next few days solar flux is expected to rise from 155 on Monday to 180 by the weekend. Planetary A index is expected to continue unsettled, with values of 20, 20 and 15 for Monday through Wednesday.
I ran across a Finnish web site devoted to photographs of aurora borealis at http://www.saunalahti.fi/~deca39/paasivu/index_eng.php3. Don't miss paging through the gallery at http://www.saunalahti.fi/~deca39/galleria/index_eng.php3. These are some fantastic photos taken in Finland and Lapland over the past couple of years.
Sunspot numbers for November 21 through 27 were 143, 124, 126, 123, 106, 100, and 112, with a mean of 119.1. 10.7 cm flux was 150.9, 149.1, 147.5, 146.2, 136.8, 142.3, and 142.6, with a mean of 145.1. Estimated planetary A indices were 50, 24, 19, 16, 17, 14, and 21, with a mean of 23.