:Product: 0331RSGA.txt :Issued: 2025 Mar 31 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 90 Issued at 2200Z on 31 Mar 2025 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at moderate levels for the past 24 hours. There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be moderate with a chance for X-class flares on days one, two, and three (01 Apr, 02 Apr, 03 Apr). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 534 km/s at 31/1444Z. Total IMF reached 11 nT at 31/1109Z. The maximum southward component of Bz reached -7 nT at 31/1515Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 37 pfu at 31/1725Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2038 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (01 Apr, 02 Apr) and quiet levels on day three (03 Apr). Protons are expected to cross threshold on day one (01 Apr), have a chance of crossing threshold on day two (02 Apr) and have a chance of crossing threshold on day three (03 Apr). III. Event probabilities 01 Apr-03 Apr Class M 75/75/75 Class X 25/25/25 Proton 80/35/25 PCAF yellow IV. Penticton 10.7 cm Flux Observed 31 Mar 172 Predicted 01 Apr-03 Apr 175/175/170 90 Day Mean 31 Mar 179 V. Geomagnetic A Indices Observed Afr/Ap 30 Mar 008/010 Estimated Afr/Ap 31 Mar 008/008 Predicted Afr/Ap 01 Apr-03 Apr 009/010-008/008-006/005 VI. Geomagnetic Activity Probabilities 01 Apr-03 Apr A. Middle Latitudes Active 20/20/10 Minor Storm 05/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/30/20 Major-severe storm 25/25/20