:Product: 1231RSGA.txt :Issued: 2025 Dec 31 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 365 Issued at 2200Z on 31 Dec 2025 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at high levels for the past 24 hours. There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be moderate with a slight chance for an X-class flare on days one, two, and three (01 Jan, 02 Jan, 03 Jan). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 616 km/s at 31/1506Z. Total IMF reached 12 nT at 31/1458Z. The maximum southward component of Bz reached -6 nT at 31/1158Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 3898 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on days one and two (01 Jan, 02 Jan) and unsettled to major storm levels on day three (03 Jan). Protons have a chance of crossing threshold on day one (01 Jan), have a slight chance of crossing threshold on day two (02 Jan) and have a slight chance of crossing threshold on day three (03 Jan). III. Event probabilities 01 Jan-03 Jan Class M 55/55/55 Class X 20/20/20 Proton 40/20/10 PCAF green IV. Penticton 10.7 cm Flux Observed 31 Dec 171 Predicted 01 Jan-03 Jan 170/165/160 90 Day Mean 31 Dec 147 V. Geomagnetic A Indices Observed Afr/Ap 30 Dec 005/008 Estimated Afr/Ap 31 Dec 007/007 Predicted Afr/Ap 01 Jan-03 Jan 014/018-014/016-028/042 VI. Geomagnetic Activity Probabilities 01 Jan-03 Jan A. Middle Latitudes Active 40/40/30 Minor Storm 30/30/40 Major-severe storm 05/05/25 B. High Latitudes Active 05/05/05 Minor Storm 20/20/15 Major-severe storm 65/65/85