:Product: 0416RSGA.txt :Issued: 2025 Apr 16 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 106 Issued at 2200Z on 16 Apr 2025 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 5 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 (17 Apr, 18 Apr, 19 Apr). IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field has been at unsettled to severe storm levels for the past 24 hours. Solar wind speed reached a peak of 663 km/s at 16/0138Z. Total IMF reached 24 nT at 16/0032Z. The maximum southward component of Bz reached -17 nT at 15/2101Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 885 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (17 Apr), unsettled to active levels on day two (18 Apr) and quiet to unsettled levels on day three (19 Apr). III. Event probabilities 17 Apr-19 Apr Class M 60/60/60 Class X 10/10/10 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 16 Apr 148 Predicted 17 Apr-19 Apr 155/150/150 90 Day Mean 16 Apr 177 V. Geomagnetic A Indices Observed Afr/Ap 15 Apr 013/ NA Estimated Afr/Ap 16 Apr 026/041 Predicted Afr/Ap 17 Apr-19 Apr 022/030-014/018-008/010 VI. Geomagnetic Activity Probabilities 17 Apr-19 Apr A. Middle Latitudes Active 35/25/15 Minor Storm 25/10/05 Major-severe storm 15/01/01 B. High Latitudes Active 10/15/15 Minor Storm 25/25/25 Major-severe storm 65/35/25