:Product: 0516RSGA.txt :Issued: 2025 May 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 136 Issued at 2200Z on 16 May 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 4 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 May, 18 May, 19 May). IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 489 km/s at 16/0721Z. Total IMF reached 9 nT at 16/1804Z. The maximum southward component of Bz reached -7 nT at 16/1842Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 455 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (17 May) and active to minor storm levels on days two and three (18 May, 19 May). III. Event probabilities 17 May-19 May Class M 60/55/55 Class X 20/15/15 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 16 May 117 Predicted 17 May-19 May 118/118/120 90 Day Mean 16 May 162 V. Geomagnetic A Indices Observed Afr/Ap 15 May 015/ NA Estimated Afr/Ap 16 May 009/011 Predicted Afr/Ap 17 May-19 May 013/ NA-021/ NA-021/ 10 VI. Geomagnetic Activity Probabilities 17 May-19 May A. Middle Latitudes Active 30/40/40 Minor Storm 10/25/25 Major-severe storm 01/05/05 B. High Latitudes Active 15/10/10 Minor Storm 25/25/25 Major-severe storm 40/60/60