Over the past reporting week (December 15-21) solar activity was little changed
from the previous seven days, although on two days (December 16-17) there were
no sunspots. Average daily sunspot numbers declined two points from 13 to 11,
and average daily solar flux bumped up one point to 73.2.
Average
planetary A index changed from 13.3 to 7.9, and average mid-latitude A index
from 9 to 5.7.
The outlook for the next month
shows daily solar flux in a big downward adjustment for the next week, compared
to the forecast in yesterday’s ARRL Letter. The average predicted solar flux
Wednesday on December 23-28 was 84.2, but in Thursday’s forecast it dropped
suddenly to 62.