:Product: 1231RSGA.txt :Issued: 2024 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 366 Issued at 2200Z on 31 Dec 2024 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: 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 30/2241Z from Region 3939 (S17E06). There are currently 9 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be moderate with a chance for X-class flares on days one and two (01 Jan, 02 Jan) and likely to be moderate with a slight chance for an X-class flare on day three (03 Jan). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 489 km/s at 31/1716Z. Total IMF reached 27 nT at 31/1735Z. The maximum southward component of Bz reached -18 nT at 31/1859Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 506 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (01 Jan), quiet to unsettled levels on day two (02 Jan) and quiet levels on day three (03 Jan). Protons have a slight chance of crossing threshold on days one and two (01 Jan, 02 Jan) and have a slight chance of crossing threshold on day three (03 Jan). III. Event probabilities 01 Jan-03 Jan Class M 80/80/70 Class X 25/25/15 Proton 20/20/15 PCAF green IV. Penticton 10.7 cm Flux Observed 31 Dec 218 Predicted 01 Jan-03 Jan 210/200/200 90 Day Mean 31 Dec 206 V. Geomagnetic A Indices Observed Afr/Ap 30 Dec 007/005 Estimated Afr/Ap 31 Dec 009/016 Predicted Afr/Ap 01 Jan-03 Jan 018/020-007/008-006/005 VI. Geomagnetic Activity Probabilities 01 Jan-03 Jan A. Middle Latitudes Active 40/20/10 Minor Storm 30/05/05 Major-severe storm 05/01/01 B. High Latitudes Active 05/15/15 Minor Storm 20/30/20 Major-severe storm 65/25/15