:Product: 0415RSGA.txt :Issued: 2025 Apr 15 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 105 Issued at 2200Z on 15 Apr 2025 IA. Analysis of Solar Active Regions and Activity from 14/2100Z to 15/2100Z: Solar activity has been at moderate levels for the past 24 hours. There are currently 4 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be moderate with a slight chance for an X-class flare on days one and two (16 Apr, 17 Apr) and likely to be moderate with a slight chance for an X-class flare on day three (18 Apr). IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z: The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed reached a peak of 617 km/s at 15/2040Z. Total IMF reached 27 nT at 15/1822Z. The maximum southward component of Bz reached -20 nT at 15/1820Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2379 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to severe storm levels on day one (16 Apr), unsettled to minor storm levels on day two (17 Apr) and unsettled to active levels on day three (18 Apr). Protons greater than 10 Mev have a slight chance of crossing threshold on days one and two (16 Apr, 17 Apr). III. Event probabilities 16 Apr-18 Apr Class M 80/75/60 Class X 15/10/10 Proton 10/10/05 PCAF green IV. Penticton 10.7 cm Flux Observed 15 Apr 153 Predicted 16 Apr-18 Apr 160/160/155 90 Day Mean 15 Apr 178 V. Geomagnetic A Indices Observed Afr/Ap 14 Apr 014/ NA Estimated Afr/Ap 15 Apr 012/015 Predicted Afr/Ap 16 Apr-18 Apr 030/054-022/030-014/018 VI. Geomagnetic Activity Probabilities 16 Apr-18 Apr A. Middle Latitudes Active 30/35/25 Minor Storm 40/25/10 Major-severe storm 20/15/01 B. High Latitudes Active 05/10/15 Minor Storm 15/25/25 Major-severe storm 75/65/35