ARLP045 Propagation de K7VVV:
November 2, 2001

Propagation Forecast Bulletin 45 ARLP045
From Tad Cook, K7VVV
Seattle, WA November 2, 2001
To all radio amateurs

ARLP045 Propagation de K7VVV

Conditions were excellent on HF going into the CQ Worldwide DX SSB Contest, but the bands deteriorated by Sunday. The predicted planetary A index for Sunday was 30, as reported in last week's bulletin. The actual planetary A index was 41, which was worse for absorption of HF signals.

Geomagnetic indices had been very low for days, but early Sunday UTC the planetary K index jumped from 2 to 6, and mid-latitude values went from 1 to 6, indicating a severe geomagnetic storm. This was Saturday evening in North America.

Another less severe geomagnetic storm began on Thursday November 1, as the interplanetary magnetic field tilted south. This lowered earth's resistance to solar wind. For more information on the interplanetary magnetic field check NASA's Space Weather site at

There were reports of fantastic conditions on 6 meters this week. W4AWI reported that 6 meters has never been this good, and he was working half the world from South Florida on October 30 and 31. He and his friends K4SUS and K2RTH worked Europe, the Middle East, Africa, South America, Siberia and Ukraine.

Average sunspot numbers this week were up 3 points over last, and average solar flux was off by 4.4 points.

Solar activity was high in September. Average daily solar flux in October was down by nearly 26 points and average sunspot numbers were off by nearly 32 compared to the previous month. The monthly averages of daily sunspot numbers for January through October were 142.7, 131, 166.7, 163.6, 135.1, 196.7, 124.6, 159.4, 229.1 and 197.4. Average daily solar flux for January through October was 166.6, 147.2, 177.7, 178.2, 148.7, 173.7, 131.3, 163.1, 233.8 and 208.1. September had the high values for this year, although there was a peak in activity spread over the last part of March and first part of April. Average sunspot numbers for the 31 days from March 20 to April 19 was 195.6 and average solar flux for the same period was 197. This was quite a bit higher than the average for the two months, because the peak in activity straddled March and April.

For the next few days solar flux is expected to be around 225 or 230. Planetary A index predicted for Friday through Monday is 12, 10, 10 and 8.

Here are some path projections for this weekend's ARRL November CW Sweepstakes.

Sunspot numbers for October 25 through 31 were 225, 239, 225, 229, 224, 205 and 212 with a mean of 222.7. 10.7 cm flux was 238.9, 236.5, 246.5, 227.2, 215.8, 226 and 221.1, with a mean of 230.3, and estimated planetary A indices were 7, 5, 6, 41, 16, 8 and 9 with a mean of 13.1.