:Product: 0526RSGA.txt :Issued: 2026 May 26 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 146 Issued at 2200Z on 26 May 2026 IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: 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 expected to be low with a chance for M-class flares on days one, two, and three (27 May, 28 May, 29 May). IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 459 km/s at 26/1918Z. Total IMF reached 9 nT at 26/1838Z. The maximum southward component of Bz reached -7 nT at 26/2021Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 23 pfu at 26/0110Z. 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 days one and two (27 May, 28 May) and quiet levels on day three (29 May). Protons greater than 10 Mev have a slight chance of crossing threshold on day one (27 May). III. Event probabilities 27 May-29 May Class M 40/40/40 Class X 05/05/05 Proton 10/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 26 May 141 Predicted 27 May-29 May 145/150/145 90 Day Mean 26 May 125 V. Geomagnetic A Indices Observed Afr/Ap 25 May 008/008 Estimated Afr/Ap 26 May 006/006 Predicted Afr/Ap 27 May-29 May 009/012-010/012-006/008 VI. Geomagnetic Activity Probabilities 27 May-29 May A. Middle Latitudes Active 25/25/20 Minor Storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/20 Minor Storm 35/35/25 Major-severe storm 30/30/25