:Product: 1228RSGA.txt :Issued: 2024 Dec 28 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 363 Issued at 2200Z on 28 Dec 2024 IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M4 event observed at 28/1121Z from Region 3932 (S18W34). There are currently 11 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 day one (29 Dec) and expected to be moderate with a chance for X-class flares on days two and three (30 Dec, 31 Dec). IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 429 km/s at 28/0149Z. Total IMF reached 8 nT at 28/0900Z. The maximum southward component of Bz reached -6 nT at 28/0900Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 608 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (29 Dec, 30 Dec) and quiet levels on day three (31 Dec). Protons have a slight chance of crossing threshold on day one (29 Dec) and have a slight chance of crossing threshold on days two and three (30 Dec, 31 Dec). III. Event probabilities 29 Dec-31 Dec Class M 70/75/75 Class X 20/25/25 Proton 10/15/15 PCAF green IV. Penticton 10.7 cm Flux Observed 28 Dec 260 Predicted 29 Dec-31 Dec 260/255/240 90 Day Mean 28 Dec 206 V. Geomagnetic A Indices Observed Afr/Ap 27 Dec 003/002 Estimated Afr/Ap 28 Dec 005/006 Predicted Afr/Ap 29 Dec-31 Dec 007/008-009/008-006/005 VI. Geomagnetic Activity Probabilities 29 Dec-31 Dec A. Middle Latitudes Active 20/20/10 Minor Storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 25/25/20 Major-severe storm 25/25/15