February 18, 2000

ZCZC AP07

QST de W1AW

Propagation Forecast Bulletin 7 ARLP007

From Tad Cook, K7VVV

Seattle, WA February 18, 2000

To all radio amateurs

SB PROP ARL ARLP007

ARLP007 Propagation de K7VVV

Solar flux and sunspot counts increased the week before last, fell last week, and the averages for both weeks were about the same. Average solar flux was down about 11 points last week, and average sunspot numbers were off by a little over one point. Last weekend had a surprising burst of geomagnetic activity, when Saturday's planetary A index was 52. The planetary K index was as high as 7, and Alaska's College A index, which is frequently higher because of its proximity to the pole, was 71. During a six hour period, from 0600-1200z, the planetary A index was 7 and 6 while the College A index was 8 and 7. These all indicate severe geomagnetic storm levels.

What should we see over the next week? For the next five days, Friday through Tuesday, solar flux is predicted to be 155, 150, 150, 145 and 145. Planetary A index for those same days is forecast to be 5, 5, 12, 8 and 8. For best HF conditions, we want a low A index in the single digits, and rising solar flux. So Sunday, February 20 with a planetary A index of 12 could be somewhat unsettled.

Solar flux for the short term is expected to bottom out near 130 around February 25, then rise to about 150 by March 1, but peak broadly and fairly low near 175 around March 4-8. The next predicted short term minimum is forecast for March 23-24. Of course these are all guesses based upon activity over previous solar rotations, which occur about every 27.5 days. Since the predicted high levels of 175 are much lower than previous rotations where solar flux was above 200, this means that the prediction is based upon sunspot regions which are currently fading. Any new sunspot areas will probably result in increased solar flux and better HF conditions. With spring coming, it would be nice to see extended worldwide openings on 10 and 12 meters again, which would accompany the high flux levels normally expected in a peak year of a solar cycle.

Sunspot numbers for February 10 through 16 were 172, 184, 157, 147, 158, 158 and 182 with a mean of 165.4. 10.7 cm flux was 175.7 170.2, 163.2, 159.9, 158.7, 156 and 160.2, with a mean of 163.4, and estimated planetary A indices were 7, 13, 52, 14, 29, 11 and 5, with a mean of 18.7.

Path projections for this weekend are **from a place in Arizona
between Tucson and Phoenix, near Eloy**.

**To Western Europe**, 80 meters 0100-0830z, 40 meters 0000-0930z, 30 meters 2330-1030z, 20 meters 1400-1600z and 2200-0000z, 17 meters 1430-2100z, 15 meters 1500-2000z, 12 meters 1600-1830z, 10 meters around 1700z.**To Eastern Europe**, 80 meters 0030-0630z, 40 meters 0000-0800z, 30 meters 2330-0830z, 20 meters 1330-1530z, 17 meters 1430-1830z, 15 meters 1530-1800z, 12 meters 1600-1630z.**To Southern Africa**, 80 meters 0030-0430z, 40 meters 0030-0500z, 30 meters and 20 meters 2330-0530z, 17 meters 2300-0100z, 15 meters 2300-0000z, 12 meters 2130-2230z, 10 meters 2000-2130z.**To South America**, 80 meters 0100-1000z, 40 meters 0030-1030z, 30 meters 0000-1100z, 20 meters 2330-1200z, 17 meters 1330-1400z and 2230-0500z, 15 meters 1400-1500z and 2130-0230z, 12 meters 1430-1600z and 2030-0200z, 10 meters 1500-0100z.**To the Caribbean**, 80 meters 0000-1130z, 40 meters 2330-1230z, 30 meters 2200-1400z, 20 meters 1300-0830z, 17 meters 1400-0100z, 15 meters 1430-0000z, 12 meters 1500-2300z, 10 meters 1530-2200z.**To Australia**, 80 and 40 meters 0930-1500z, 30 meters 0900-1500z, 20 meters 0830-1530z, 17 meters 0700-1100z and 1500-1630z, 15 meters around 1500z and around 0430z.**To Japan**, 80 meters 0800-1500z, 40 meters 0700-1500z, 30 meters 0630-1600z, 20 meters 0530-1700z, 17 meters 2100-0430z, 15 meters 2100-0400z, 12 meters 2130-0230z, 10 meters 2200-0130z.