Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 4 December 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 338 Issued at 2200Z on 04 Dec 2021

IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4 event observed at 04/0515Z from Region 2898 (S24, l=236). There are currently 3 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 (05 Dec, 06 Dec, 07 Dec).

IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 534 km/s at 04/0257Z. Total IMF reached 9 nT at 03/2316Z. The maximum southward component of Bz reached -6 nT at 04/0028Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1220 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (05 Dec) and quiet to unsettled levels on days two and three (06 Dec, 07 Dec).

III. Event probabilities 05 Dec-07 Dec
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 04 Dec 088
Predicted 05 Dec-07 Dec 084/082/080
90 Day Mean 04 Dec 088

V. Geomagnetic A Indices
Observed Afr/Ap 03 Dec 004/006
Estimated Afr/Ap 04 Dec 010/010
Predicted Afr/Ap 05 Dec-07 Dec 009/012-008/008-008/008

VI. Geomagnetic Activity Probabilities 05 Dec-07 Dec
A. Middle Latitudes
Active 30/20/15
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/25/25
Major-severe storm 40/30/20