:Product: 0520RSGA.txt :Issued: 2025 May 21 0200 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 140 Issued at 2200Z on 20 May 2025 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: 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 expected to be low with a chance for M-class flares on days one, two, and three (21 May, 22 May, 23 May). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 617 km/s at 20/2158Z. Total IMF reached 10 nT at 20/1352Z. The maximum southward component of Bz reached -8 nT at 20/1037Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1309 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (21 May, 22 May) and quiet to active levels on day three (23 May). III. Event probabilities 21 May-23 May Class M 35/35/35 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 May 119 Predicted 21 May-23 May 118/120/120 90 Day Mean 20 May 159 V. Geomagnetic A Indices Observed Afr/Ap 19 May 010/ 010 Estimated Afr/Ap 20 May 012/013 Predicted Afr/Ap 21 May-23 May 010/012-007/010-009/012 VI. Geomagnetic Activity Probabilities 21 May-23 May A. Middle Latitudes Active 30/15/15 Minor Storm 15/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/25/25 Major-severe storm 45/25/20