:Product: 0831RSGA.txt :Issued: 2025 Aug 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 243 Issued at 2200Z on 31 Aug 2025 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 10 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 days one, two, and three (01 Sep, 02 Sep, 03 Sep). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 499 km/s at 31/1856Z. Total IMF reached 10 nT at 31/0249Z. The maximum southward component of Bz reached -7 nT at 31/0720Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 393 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to major storm levels on day one (01 Sep), active to severe storm levels on day two (02 Sep) and quiet to active levels on day three (03 Sep). Protons have a slight chance of crossing threshold on days one, two, and three (01 Sep, 02 Sep, 03 Sep). III. Event probabilities 01 Sep-03 Sep Class M 65/65/65 Class X 20/20/20 Proton 10/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 31 Aug 217 Predicted 01 Sep-03 Sep 215/210/200 90 Day Mean 31 Aug 143 V. Geomagnetic A Indices Observed Afr/Ap 30 Aug 008/008 Estimated Afr/Ap 31 Aug 007/010 Predicted Afr/Ap 01 Sep-03 Sep 016/020-039/055-009/010 VI. Geomagnetic Activity Probabilities 01 Sep-03 Sep A. Middle Latitudes Active 25/25/35 Minor Storm 40/35/15 Major-severe storm 30/35/01 B. High Latitudes Active 05/05/10 Minor Storm 15/15/30 Major-severe storm 79/85/50