ARLP037 Propagation de K7VVV:
September 7, 2001

Propagation Forecast Bulletin 37 ARLP037
From Tad Cook, K7VVV
Seattle, WA September 7, 2001
To all radio amateurs

ARLP037 Propagation de K7VVV

Compared to the previous seven days, average solar flux rose Nearly ten points this week, but average sunspot numbers dropped about the same amount. There seems to be quite a bit of new activity emerging. Earth is exiting a solar wind, which brought planetary A indices to 17 and 20 on Monday and Tuesday. There were nine 3-hour periods out of the two days which had a planetary K index of four.

A new sunspot group number 9608 is emerging on the southeastern limb of the solar disk, and this could bring more flare activity and coronal mass ejections. The current outlook calls for solar flux to rise over the next few days, to 225 on Friday, and around 230 on Saturday through Tuesday. This would be a big change, because flux values have not been above this value since April 1. This could be an exiting fall DX season, and since solar activity will be declining, perhaps the best for years to come.

The current forecast shows a planetary A index around ten for the next ten days, but of course this could change.

Shel Shallon has a new version 2.02 of W6ELprop, and you can download it for free from The new version has added some nice features, such as continuous scrolling (the spreadsheet doesn't stop at 0000 UTC, but you can now scroll backward and forward continuously).

Several people asked for path projections for the Worked All Europe Phone Contest this weekend. Since these are the same paths used for a similar projection in ARLP033 on August 10, by comparing the two you can see the effects of the change of season over the past month as we move toward the fall equinox. You can find old copies of this bulletin on the ARRL web site.

The author's internet service provider closed its doors abruptly in the final week of August, so the old email address has not worked since then, even though it is not bouncing mail. Best to use for correspondence.

Here are the path projections to Europe for this weekend.

Sunspot numbers for August 30 through September 5 were 138, 142, 153, 141, 168, 168 and 175 with a mean of 155. 10.7 cm flux was 199.2, 188.7, 184.1, 182.5, 198.7, 218.4 and 218.3, with a mean of 198.6, and estimated planetary A indices were 13, 16, 8, 7, 17, 20 and 10 with a mean of 13.