Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 October 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 294 Issued at 2200Z on 21 Oct 2021

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (22 Oct, 23 Oct, 24 Oct).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 561 km/s at 21/0105Z. Total IMF reached 12 nT at 20/2139Z. The maximum southward component of Bz reached -5 nT at 20/2316Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 144 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (22 Oct) and quiet levels on days two and three (23 Oct, 24 Oct).

III. Event probabilities 22 Oct-24 Oct
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Oct 082
Predicted 22 Oct-24 Oct 082/083/084
90 Day Mean 21 Oct 082

V. Geomagnetic A Indices
Observed Afr/Ap 20 Oct 005/004
Estimated Afr/Ap 21 Oct 008/008
Predicted Afr/Ap 22 Oct-24 Oct 008/008-006/005-006/005

VI. Geomagnetic Activity Probabilities 22 Oct-24 Oct
A. Middle Latitudes
Active 20/15/15
Minor Storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/20/20
Major-severe storm 25/20/20