ZCZC AP23
QST de W1AW
Propagation Forecast Bulletin 23 ARLP023
From Tad Cook, K7VVV
Seattle, WA June 6, 1997
To all radio amateurs
SB PROP ARL ARLP023
ARLP023 Propagation de K7VVV
Average Solar flux was down about 3 points last week compared to the previous week. The sunspot count was down also. Geomagnetic conditions were stable, with the only unsettled period on June 3 when the Planetary A index was 10 and the K index rose to 4.
Over the next few weeks the solar flux should rise to around 80 by mid month, then drift back to the mid seventies. Geomagnetic activity should stay stable.
Dr. George C. Rybicki, KE8YX, of the NASA Lewis Research Center wrote to say that a recent article in a journal of the American Geophysical Union reports that the next solar cycle is predicted to have a mean smoothed sunspot maximum of 160, about the same as the last cycle. He also reports a popular theory which states that even numbered cycles are followed by a bigger odd numbered cycle, and this is observed without exception for the past 150 years. The next cycle is number 23, and he says it may be a record, like cycle 19 in the late 1950s.
Sunspot Numbers for May 29 through June 4 were 27, 35, 29, 33, 35, 20 and 16 with a mean of 27.9. 10.7 cm flux was 75.6, 75.1, 72.5, 77.3, 76.9, 75.2 and 73.9, with a mean of 75.2, and estimated planetary A indices were 3, 7, 9, 6, 7, 10, and 5, with a mean of 6.7.