:Product: 1213RSGA.txt :Issued: 2021 Dec 13 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 347 Issued at 2200Z on 13 Dec 2021 IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 12/2114Z. 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 (14 Dec, 15 Dec, 16 Dec). IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 336 km/s at 13/0704Z. Total IMF reached 9 nT at 13/0818Z. The maximum southward component of Bz reached -6 nT at 13/0122Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 354 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (14 Dec, 16 Dec) and quiet to active levels on day two (15 Dec). III. Event probabilities 14 Dec-16 Dec Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 13 Dec 081 Predicted 14 Dec-16 Dec 082/082/084 90 Day Mean 13 Dec 086 V. Geomagnetic A Indices Observed Afr/Ap 12 Dec 002/002 Estimated Afr/Ap 13 Dec 007/006 Predicted Afr/Ap 14 Dec-16 Dec 007/008-010/012-007/008 VI. Geomagnetic Activity Probabilities 14 Dec-16 Dec A. Middle Latitudes Active 15/30/25 Minor Storm 01/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 25/30/30 Major-severe storm 20/40/30