:Product: 0520RSGA.txt :Issued: 2026 May 20 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 140 Issued at 2200Z on 20 May 2026 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 4 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on day one (21 May) and expected to be low with a chance for M-class flares on days two and three (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 542 km/s at 20/0222Z. Total IMF reached 6 nT at 20/0158Z. The maximum southward component of Bz reached -5 nT at 19/2359Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1716 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (21 May), quiet to active levels on day two (22 May) and quiet levels on day three (23 May). III. Event probabilities 21 May-23 May Class M 20/25/25 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 20 May 114 Predicted 21 May-23 May 110/108/115 90 Day Mean 20 May 124 V. Geomagnetic A Indices Observed Afr/Ap 19 May 018/019 Estimated Afr/Ap 20 May 008/008 Predicted Afr/Ap 21 May-23 May 007/012-007/009-007/008 VI. Geomagnetic Activity Probabilities 21 May-23 May A. Middle Latitudes Active 20/30/20 Minor Storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/20 Minor Storm 35/35/35 Major-severe storm 25/30/25