:Product: 0401RSGA.txt :Issued: 2026 Apr 01 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 91 Issued at 2200Z on 01 Apr 2026 IA. Analysis of Solar Active Regions and Activity from 31/2100Z to 01/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 9 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 (02 Apr, 03 Apr, 04 Apr). IIA. Geophysical Activity Summary 31/2100Z to 01/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 511 km/s at 01/1138Z. Total IMF reached 16 nT at 01/1156Z. The maximum southward component of Bz reached -9 nT at 01/1228Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2587 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (02 Apr), quiet to active levels on day two (03 Apr) and unsettled to active levels on day three (04 Apr). Protons have a slight chance of crossing threshold on days one, two, and three (02 Apr, 03 Apr, 04 Apr). III. Event probabilities 02 Apr-04 Apr Class M 55/55/55 Class X 15/15/15 Proton 10/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 01 Apr 142 Predicted 02 Apr-04 Apr 145/140/135 90 Day Mean 01 Apr 138 V. Geomagnetic A Indices Observed Afr/Ap 31 Mar 008/007 Estimated Afr/Ap 01 Apr 011/014 Predicted Afr/Ap 02 Apr-04 Apr 014/022-015/018-015/021 VI. Geomagnetic Activity Probabilities 02 Apr-04 Apr A. Middle Latitudes Active 40/40/35 Minor Storm 35/20/15 Major-severe storm 10/05/05 B. High Latitudes Active 05/10/10 Minor Storm 25/25/20 Major-severe storm 70/60/45