:Product: 0818RSGA.txt :Issued: 2025 Aug 18 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 230 Issued at 2200Z on 18 Aug 2025 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 6 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 on days one and two (19 Aug, 20 Aug) and likely to be low with a slight chance for an M-class flare on day three (21 Aug). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 414 km/s at 18/0603Z. Total IMF reached 11 nT at 18/1036Z. The maximum southward component of Bz reached -7 nT at 18/1058Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2222 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on days one and two (19 Aug, 20 Aug) and quiet to active levels on day three (21 Aug). III. Event probabilities 19 Aug-21 Aug Class M 05/05/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Aug 114 Predicted 19 Aug-21 Aug 112/108/110 90 Day Mean 18 Aug 136 V. Geomagnetic A Indices Observed Afr/Ap 17 Aug 007/ 005 Estimated Afr/Ap 18 Aug 008/010 Predicted Afr/Ap 19 Aug-21 Aug 018/028-018/025-012/015 VI. Geomagnetic Activity Probabilities 19 Aug-21 Aug A. Middle Latitudes Active 35/35/30 Minor Storm 30/25/15 Major-severe storm 10/05/01 B. High Latitudes Active 05/10/15 Minor Storm 20/25/30 Major-severe storm 65/55/40