:Product: 1220RSGA.txt :Issued: 2025 Dec 20 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 354 Issued at 2200Z on 20 Dec 2025 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at moderate levels for the past 24 hours. There are currently 6 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on days one, two, and three (21 Dec, 22 Dec, 23 Dec). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 511 km/s at 19/2100Z. Total IMF reached 5 nT at 20/1752Z. The maximum southward component of Bz reached -3 nT at 20/1236Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 7317 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (21 Dec), quiet to minor storm levels on day two (22 Dec) and unsettled to minor storm levels on day three (23 Dec). III. Event probabilities 21 Dec-23 Dec Class M 10/10/20 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Dec 120 Predicted 21 Dec-23 Dec 120/120/125 90 Day Mean 20 Dec 148 V. Geomagnetic A Indices Observed Afr/Ap 19 Dec 004/006 Estimated Afr/Ap 20 Dec 006/006 Predicted Afr/Ap 21 Dec-23 Dec 005/005-015/022-022/030 VI. Geomagnetic Activity Probabilities 21 Dec-23 Dec A. Middle Latitudes Active 10/35/35 Minor Storm 01/30/30 Major-severe storm 01/10/10 B. High Latitudes Active 15/10/05 Minor Storm 20/25/20 Major-severe storm 10/65/70