:Product: 0511RSGA.txt :Issued: 2024 May 11 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 132 Issued at 2200Z on 11 May 2024 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a X5 event observed at 11/0123Z from Region 3664 (S18W62). There are currently 8 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be high on days one, two, and three (12 May, 13 May, 14 May). IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been at severe storm levels for the past 24 hours. Solar wind speed reached a peak of 993 km/s at 11/1433Z. Total IMF reached 73 nT at 10/2305Z. The maximum southward component of Bz reached -50 nT at 11/0048Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 116 pfu at 11/0910Z. Protons greater than 100 MeV at geosynchronous orbit reached a peak level of 7 pfu at 11/0715Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 119 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at severe storm levels on day one (12 May), active to severe storm levels on day two (13 May) and unsettled to minor storm levels on day three (14 May). Protons are expected to cross threshold on days one and two (12 May, 13 May) and are likely to cross threshold on day three (14 May). III. Event probabilities 12 May-14 May Class M 95/95/95 Class X 75/75/75 Proton 99/99/60 PCAF red IV. Penticton 10.7 cm Flux Observed 11 May 214 Predicted 12 May-14 May 220/220/215 90 Day Mean 11 May 165 V. Geomagnetic A Indices Observed Afr/Ap 10 May 080/157 Estimated Afr/Ap 11 May 268/317 Predicted Afr/Ap 12 May-14 May 114/156-041/060-015/020 VI. Geomagnetic Activity Probabilities 12 May-14 May A. Middle Latitudes Active 05/15/35 Minor Storm 40/35/30 Major-severe storm 55/55/15 B. High Latitudes Active 01/01/05 Minor Storm 05/05/20 Major-severe storm 95/95/70