ZCZC AP10
QST de W1AW
Propagation Forecast Bulletin 10 ARLP010
From Tad Cook, KT7H
Seattle, WA March 7, 1997
To all radio amateurs
SB PROP ARL ARLP010
ARLP010 Propagation de KT7H
There was no change in solar flux or sunspot activity last week, as we continue to experience the bottom of the solar cycle. There were some geomagnetic disturbances though, with the worst conditions on the last day of February when the Planetary A Index reached 32 and the highest Planetary K index was 6.
Over the next few weeks the geomagnetic field should stay predominantly quiet, except that a recurrent coronal hole with high speed solar wind could rotate into view around March 26 and 27. Solar flux should stay in the low to mid seventies, with the Sun mostly spotless.
Last week this bulletin reported that the solar flux on February 26 was 74. A closer approximation is 73.8 for that date. This does not change the average flux for the week.
Sunspot Numbers for February 27 through March 5 were 0 each day with a mean of 0. 10.7 cm flux was 73.8, 72.8, 73.5, 72.3, 74, 74 and 74.6, with a mean of 73.6. Estimated planetary A indices for the same period were 20, 32, 10, 12, 5, 4, and 7, with a mean of 12.9.