:Product: 0516RSGA.txt :Issued: 2024 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 137 Issued at 2200Z on 16 May 2024 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 16/0804Z from Region 3685 (S13E64). There are currently 13 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and 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 major storm levels for the past 24 hours. Solar wind speed reached a peak of 529 km/s at 16/0528Z. Total IMF reached 17 nT at 16/0611Z. The maximum southward component of Bz reached -12 nT at 16/0656Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 22 pfu at 16/1115Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 602 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and three (17 May, 19 May) and quiet to unsettled levels on day two (18 May). Protons greater than 10 Mev have a chance of crossing threshold on day one (17 May). III. Event probabilities 17 May-19 May Class M 40/40/40 Class X 10/10/10 Proton 25/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 16 May 207 Predicted 17 May-19 May 200/190/180 90 Day Mean 16 May 166 V. Geomagnetic A Indices Observed Afr/Ap 15 May 010/010 Estimated Afr/Ap 16 May 019/029 Predicted Afr/Ap 17 May-19 May 013/015-008/008-012/015 VI. Geomagnetic Activity Probabilities 17 May-19 May A. Middle Latitudes Active 35/20/35 Minor Storm 15/05/15 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/10 Minor Storm 25/25/25 Major-severe storm 50/25/50