:Product: 1217RSGA.txt :Issued: 2025 Dec 17 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 351 Issued at 2200Z on 17 Dec 2025 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 5 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 (18 Dec, 19 Dec, 20 Dec). IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 744 km/s at 17/2030Z. Total IMF reached 8 nT at 17/1801Z. The maximum southward component of Bz reached -7 nT at 17/1241Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1632 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (18 Dec) and quiet to unsettled levels on days two and three (19 Dec, 20 Dec). III. Event probabilities 18 Dec-20 Dec Class M 15/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Dec 119 Predicted 18 Dec-20 Dec 118/115/110 90 Day Mean 17 Dec 150 V. Geomagnetic A Indices Observed Afr/Ap 16 Dec 006/012 Estimated Afr/Ap 17 Dec 010/014 Predicted Afr/Ap 18 Dec-20 Dec 014/015-009/010-008/008 VI. Geomagnetic Activity Probabilities 18 Dec-20 Dec A. Middle Latitudes Active 35/25/20 Minor Storm 15/10/05 Major-severe storm 05/01/01 B. High Latitudes Active 10/15/15 Minor Storm 25/25/25 Major-severe storm 50/35/25