:Product: 1217RSGA.txt :Issued: 2024 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 352 Issued at 2200Z on 17 Dec 2024 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. The largest solar event of the period was a C4 event observed at 17/0130Z from Region 3917 (S07, L=010). There are currently 5 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares 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 minor storm levels for the past 24 hours. Solar wind speed reached a peak of 701 km/s at 17/0821Z. Total IMF reached 31 nT at 17/0839Z. The maximum southward component of Bz reached -11 nT at 17/0701Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 126 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (18 Dec) and quiet levels on days two and three (19 Dec, 20 Dec). III. Event probabilities 18 Dec-20 Dec Class M 30/40/40 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Dec 170 Predicted 18 Dec-20 Dec 170/175/190 90 Day Mean 17 Dec 200 V. Geomagnetic A Indices Observed Afr/Ap 16 Dec 011/014 Estimated Afr/Ap 17 Dec 023/031 Predicted Afr/Ap 18 Dec-20 Dec 013/012-005/005-005/005 VI. Geomagnetic Activity Probabilities 18 Dec-20 Dec A. Middle Latitudes Active 35/10/10 Minor Storm 15/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/20/20 Major-severe storm 50/15/15