ZCZC AP22
QST de W1AW
Propagation Forecast Bulletin 22 ARLP022
From Tad Cook, K7VVV
Seattle, WA May 25, 2001
To all radio amateurs
SB PROP ARL ARLP022
ARLP022 Propagation de K7VVV
Geomagnetic conditions were quieter this week, and solar flux and sunspot numbers were a little higher. Average solar flux was up nearly 10 points and average sunspot numbers were up by about 7. Last Saturday had unsettled to active geomagnetic conditions, with both the planetary and mid-latitude K indices at 4 over two of the eight three-hour reporting periods, but the planetary A index for the day was only 12.
Solar flux is expected to peak over the next week. Solar flux for Friday is predicted at 165, and then 170 for Saturday through Tuesday. The predicted planetary A index for Friday through Monday is 8, 10, 20 and 12. The earth is currently inside a solar wind stream flowing from a coronal hole. Sunspot 9463 is rapidly growing at the center of the disk, and holds the greatest chance of emitting solar flares. A holographic image of the far side of the sun shows no substantial sunspots that might rotate into view in the next couple of weeks.
This weekend HF contesters will be enjoying the CQ Worldwide WPX CW Contest. Conditions should be good on Saturday, but may get rough on Sunday with higher geomagnetic activity.
Sunspot numbers for May 17 through 23 were 137, 109, 92, 99, 118, 159 and 192 with a mean of 129.4. 10.7 cm flux was 147.4, 138.2, 141.3, 141.5, 150.1, 152 and 158.7, with a mean of 147, and estimated planetary A indices were 9, 11, 12, 10, 8, 9 and 11 with a mean of 10.