ZCZC AP46
QST de W1AW
Propagation Forecast Bulletin 46 ARLP046
From Tad Cook, K7VVV
Seattle, WA November 13, 1998
To all radio amateurs
SB PROP ARL ARLP046
ARLP046 Propagation de K7VVV
Solar activity was much higher over the past week. Average sunspot numbers jumped almost 34 points to 118.6 and average solar flux was up about 25 points to 151.2. The average for solar flux for the 90 days prior to this week was 131.3, and flux values were above this level on every day of this week, which is a good sign of an upward trend.
The most active day was Monday, when the solar flux was above 160. Unfortunately for HF operators this was also the second of two days of geomagnetic storms, with Sunday's planetary A index at 68 and Monday's at 78. The high latitude A index was 130 on Monday. It was a weekend of uneven conditions for the ARRL Sweepstakes.
These conditions which meant poor propagation on HF produced some interesting effects on VHF. W1JJM in Rhode Island reported working CX8BE in Uruguay on six meters, and W1LP in Massachusetts heard a beacon from Malawi on six as well. W1LP also reported a whole list of stations around North America worked via aurora on two meter CW.
For this weekend solar activity is expected to retreat a little, with the solar flux on Friday through Sunday forecast at 140, 140 and 138. Planetary A index over the same three days is predicted to be 15, 20 and 10. Solar flux is expected to dip below 130 after November 18, and bottom out around 120 from November 20 through 24.
Flux values should rise above 130 after November 27, and peak below 150 around December 1 and 2. Geomagnetic conditions are expected to be unstable until November 18. This is all based on activity during the previous solar rotation, and new active areas on the sun could appear at any time.
Next week look out for the big Leonid meteor storm on November 17. This should be a peak year in the Leonid's 33 year cycle, and the best viewing should be over Northern Asia.
Sunspot Numbers for November 5 through November 11 were 137, 142, 144, 137, 107, 81 and 82 with a mean of 118.6. 10.7 cm flux was 152.7, 140.9, 148.5, 152.7, 162.4, 153.8 and 147.1, with a mean of 151.2, and estimated planetary A indices were 9, 22, 25, 68, 78, 6 and 4, with a mean of 30.3.