:Product: 1211RSGA.txt :Issued: 2023 Dec 11 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 345 Issued at 2200Z on 11 Dec 2023 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 10/2243Z from Region 3511 (S23W71). There are currently 6 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 (12 Dec) and expected to be low with a chance for M-class flares on days two and three (13 Dec, 14 Dec). IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 472 km/s at 10/2259Z. Total IMF reached 6 nT at 11/1554Z. The maximum southward component of Bz reached -3 nT at 11/0159Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1338 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (12 Dec, 14 Dec) and quiet to active levels on day two (13 Dec). Protons greater than 10 Mev have a slight chance of crossing threshold on day one (12 Dec). III. Event probabilities 12 Dec-14 Dec Class M 55/40/40 Class X 10/05/05 Proton 10/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 11 Dec 126 Predicted 12 Dec-14 Dec 120/122/122 90 Day Mean 11 Dec 149 V. Geomagnetic A Indices Observed Afr/Ap 10 Dec 004/003 Estimated Afr/Ap 11 Dec 004/005 Predicted Afr/Ap 12 Dec-14 Dec 010/010-010/012-007/008 VI. Geomagnetic Activity Probabilities 12 Dec-14 Dec A. Middle Latitudes Active 15/25/10 Minor Storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 20/20/20 Major-severe storm 10/20/20