QST de W1AW
Propagation Forecast Bulletin 53 ARLP053
From Tad Cook, K7VVV
Seattle, WA December 30, 1999
To all radio amateurs
SB PROP ARL ARLP053
ARLP053 Propagation de K7VVV
Solar flux and sunspot numbers declined over the past week. Average solar flux for the past seven days was nearly 35 points lower than the previous seven. The decline is expected to continue through the weekend, with predicted solar flux for Thursday through Saturday of 140, 135 and 130. Solar flux should rise again around next Wednesday, and hit 150 around January 8, rising about 10 points per day and then peaking around 210 on January 14 or 15.
Planetary A index for Thursday through Saturday is predicted at 10, 15 and 25, so the New Year should yield some geomagnetic disturbances. The geomagnetic field is expected to be at unsettled to minor storm levels through Monday due to recurrent coronal hole effects. This should quiet down again around January 5.
WN6K wrote last week about his web site devoted to graphs of solar and geomagnetic indices at http://idt.net/~wngk19/index.html.
Also check an MSNBC story about geomagnetic storms in the new year at http://www.msnbc.com/news/251370.asp. NASA has an article at http://www.spacescience.com/newhome/headlines/ast29dec99_1.htm which talks about energy from solar wind squeezing the earth's magnetosphere.
N0ZOD, who is Section Emergency Coordinator for Minnesota ARES wrote this week to ask about propagation to the Far East on Friday night, when some US hams will be trying to contact hams in the area which first experiences the year 2000. Path projections for this week will concentrate on reaching the Far East from the United States on Friday.
Sunspot numbers for December 23 through 29 were 112, 149, 141, 125, 109, 77 and 123 with a mean of 119.4. 10.7 cm flux was 198.4, 182.4, 178.4, 177, 161.7, 150.4 and 143.7, with a mean of 170.3, and estimated planetary A indices were 5, 10, 10, 2, 6, 7 and 7, with a mean of 6.7.
Path projections for this Friday will be from the West Coast, East Coast, and center of the continental United States to New Zealand, Australia and Japan on 80, 40, 20, 17 and 15 meters.