:Product: 0819RSGA.txt :Issued: 2025 Aug 19 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 231 Issued at 2200Z on 19 Aug 2025 IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at moderate levels for the past 24 hours. There are currently 3 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on days one, two, and three (20 Aug, 21 Aug, 22 Aug). IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 707 km/s at 19/1521Z. Total IMF reached 19 nT at 19/1231Z. The maximum southward component of Bz reached -11 nT at 19/1636Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 471 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (20 Aug), quiet to active levels on day two (21 Aug) and quiet levels on day three (22 Aug). III. Event probabilities 20 Aug-22 Aug Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 19 Aug 116 Predicted 20 Aug-22 Aug 115/115/115 90 Day Mean 19 Aug 136 V. Geomagnetic A Indices Observed Afr/Ap 18 Aug 005/ 007 Estimated Afr/Ap 19 Aug 015/021 Predicted Afr/Ap 20 Aug-22 Aug 018/025-012/015-007/008 VI. Geomagnetic Activity Probabilities 20 Aug-22 Aug A. Middle Latitudes Active 35/30/20 Minor Storm 30/15/05 Major-severe storm 10/01/01 B. High Latitudes Active 05/15/15 Minor Storm 20/30/30 Major-severe storm 70/40/25