:Product: 1226RSGA.txt :Issued: 2024 Dec 26 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 361 Issued at 2200Z on 26 Dec 2024 IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M7 event observed at 26/0315Z from Region 3938 (N21E40). There are currently 11 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be moderate with a slight chance for an X-class flare on days one, two, and three (27 Dec, 28 Dec, 29 Dec). IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 454 km/s at 25/2146Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 867 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (27 Dec), quiet to unsettled levels on day two (28 Dec) and quiet levels on day three (29 Dec). Protons have a slight chance of crossing threshold on days one, two, and three (27 Dec, 28 Dec, 29 Dec). III. Event probabilities 27 Dec-29 Dec Class M 75/75/75 Class X 10/10/10 Proton 10/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 26 Dec 256 Predicted 27 Dec-29 Dec 255/260/255 90 Day Mean 26 Dec 205 V. Geomagnetic A Indices Observed Afr/Ap 25 Dec 005/004 Estimated Afr/Ap 26 Dec 005/007 Predicted Afr/Ap 27 Dec-29 Dec 009/010-007/008-006/005 VI. Geomagnetic Activity Probabilities 27 Dec-29 Dec A. Middle Latitudes Active 30/20/10 Minor Storm 10/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/25/20 Major-severe storm 40/30/15