Average daily sunspot
numbers this week (May 4-10) were 17.1, down from 25.1 last week. Average daily
solar flux declined from 76.9 to 71.5.
There were three consecutive days with
zero sunspots this week, May 9-11. Spaceweather.com noted that Thursday was the
thirty-third day with zero sunspots in 2017, and through all of 2016 there were
32 days with no sunspots. Being early May, this indicates an acceleration of the
decline of the current solar cycle.
Predicted solar flux is 71 on May 12-13,
70 on May 14-17, 80 on May 18-23, 77 on May 24-27, 75 on May 28 through June 1,
73 on June 2, 72 on June 3-4, 70 on June 5-8, 72 on June 9-10, 75 on June 11,
and 80 on June 12-19.
Predicted planetary A index is 6 on May
12, 5 on May 13-16, 15 on May 17-18, then 8, 15, 30, 20, 10 and 8 on May 19-24,
5 on May 25 through June 3, 8 on June 4, 5 on June 5-7, then 8, 5, 5 and 8 on
June 8-11, then 15, 30, 15 and 8 on June 12-15.
Both above Ap and 10.7 cm SF forecasts
are from Wednesday May 10. As of 1430 UTC Friday the Thursday May 11 forecast
(normally out after 2100 UTC daily) was still unavailable.
You can check ftp://ftp.swpc.noaa.gov/pub/forecasts/45DF/ for
daily updates of predicted Ap (planetary A index) and solar flux predictions.
OK1HH gives us his geomagnetic activity forecast for May 12-June 7, 2017.
Geomagnetic field will be:
Quiet on May 14-15, June 1,
Mostly quiet on May 13, June 4
Quiet to unsettled May 12, 23-30, June 3, 5-7
Quiet to active on May 16, 20, 21-22, June 2
Active to disturbed on May (17-19, 31)
