ZCZC AP47
QST de W1AW
Propagation Forecast Bulletin 47 ARLP047
From Tad Cook, K7VVV
Seattle, WA November 21, 1997
To all radio amateurs
SB PROP ARL ARLP047
ARLP047 Propagation de K7VVV
Solar activity was up a little this week compared to last, and geomagnetic conditions were quiet. The average solar flux for the previous 90 days rose one point from 90 to 91, and the solar flux was above these numbers every day this week. This indicates an upward trend. The 90 day average was five points lower only a month ago.
Solar activity is expected to remain high, with solar flux values over 100. An active area (region 8100) is expected to return November 23, and this may send solar flux to the 110 mark from November 26 to December 1. Flux values are not expected to drop below 95 until December 10. This region, which produced X-class solar flares on November 4 and 6, may produce M-class flare activity this time around. Watch for active geomagnetic conditions around November 20 to 24 and again around December 3.
Ten and fifteen meters should open during the day with higher solar flux values. The best conditions, with high solar flux and low geomagnetic conditions, are currently forecast for the CQ Worldwide CW DX Contest after Thanksgiving.
With solar activity higher, it is fun to watch the progress of cycle 23 with a plotting program which graphs the daily numbers over time. Check out the Solar Data Plotting software from WA4TTK on the web at http://edge.net/~scraig/. This program automatically grabs the solar data from this weekly propagation bulletin to update its database. If you need to fill in gaps in your data, grab old propagation bulletins from the ARRL web site at http://www.arrl.org/w1aw/prop/1997-index.html.
Sunspot Numbers for November 13 through 19 were 41, 48, 35, 58, 74, 71 and 62 with a mean of 55.6. 10.7 cm flux was 90, 93, 96.2, 96.2, 94.2, 91.5 and 96.5, with a mean of 93.9, and estimated planetary A indices were 4, 11, 7, 9, 7, 9, and 3, with a mean of 7.1.