:Product: 0421RSGA.txt :Issued: 2025 Apr 21 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 111 Issued at 2200Z on 21 Apr 2025 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at moderate levels for the past 24 hours. There are currently 8 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (22 Apr, 23 Apr, 24 Apr). IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 745 km/s at 21/1336Z. Total IMF reached 18 nT at 21/0733Z. The maximum southward component of Bz reached -14 nT at 21/0803Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 452 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to major storm levels on day one (22 Apr), quiet to minor storm levels on day two (23 Apr) and quiet to active levels on day three (24 Apr). III. Event probabilities 22 Apr-24 Apr Class M 40/40/40 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Apr 163 Predicted 22 Apr-24 Apr 163/160/160 90 Day Mean 21 Apr 173 V. Geomagnetic A Indices Observed Afr/Ap 20 Apr 011/ 14 Estimated Afr/Ap 21 Apr 028/039 Predicted Afr/Ap 22 Apr-24 Apr 020/032-016/020-014/018 VI. Geomagnetic Activity Probabilities 22 Apr-24 Apr A. Middle Latitudes Active 35/40/30 Minor Storm 40/30/15 Major-severe storm 20/10/01 B. High Latitudes Active 05/05/15 Minor Storm 15/20/30 Major-severe storm 80/75/45