QST de W1AW  
> Propagation Forecast Bulletin 39  ARLP039
> From Tad Cook, K7VVV
> Seattle, WA  September 20, 2002
> To all radio amateurs 
> 
> SB PROP ARL ARLP039
> ARLP039 Propagation de K7VVV
> 
> Average sunspot numbers were up a bit this week compared to last,
> and solar flux on average was about the same. Solar flux peaked in
> the short term on September 10 at 220.5 and has been mostly
> declining since. Solar flux on Tuesday through Thursday of this week
> was 194, 176.8 and 165.3, and for Friday though Sunday is predicted
> at 165, 160 and 155. Sunday's value may continue for a few more days
> and should be the minimum for the near term. Assuming returning
> activity from the current solar rotation, solar flux is expected to
> peak again around October 6-11.
> 
> The big news this week though is the autumnal equinox, set for early
> this Monday UTC. 10-meters is seasonally best around this time, and
> K7SS reports a great opening during the recent Worked All Europe
> contest between the West Coast and Europe on 10-meters on Friday and
> Saturday mornings. He is also hearing Africa via longpath on
> 15-meters at night, and 20-meters is staying open quite late toward
> the west.
> 
> Gary, N8MJZ asks why the equinox is good for DX. Around the equinox
> the southern and northern hemispheres get approximately an equal
> amount of sunlight. This means that there aren't any short days
> anywhere on the planet with the accompanying early winter band
> closings, and with more equal solar radiation around the earth MUFs
> are generally higher.
> 
> Go to
> www.ucar.edu/communications/newsreleases/2002/space.html for
> an article about a new space weather forecasting initiative funded
> by the National Science Foundation. This article also references the
> ''Windows to the Universe'' site at www.windows.ucar.edu/,
> which has a number of interesting features, including views of
> electron densities in the ionosphere and details on ionospheric
> sounding.
> 
> Sunspot numbers for September 12 through 18 were 258, 246, 256, 168,
> 190, 228 and 225, with a mean of 224.4. 10.7 cm flux was 212.4,
> 206.1, 206.9, 187.8, 182.6, 194, and 176.8, with a mean of 195.2.
> Estimated planetary A indices were 17, 16, 11, 8, 8, 13, and 14,
> with a mean of 12.4.
>