:Product: 0523RSGA.txt :Issued: 2018 May 23 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 143 Issued at 2200Z on 23 May 2018 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 23/1821Z. There are currently 2 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one, two, and three (24 May, 25 May, 26 May). IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 548 km/s at 23/1718Z. Total IMF reached 11 nT at 23/0546Z. The maximum southward component of Bz reached -9 nT at 23/0523Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 812 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (24 May), quiet to unsettled levels on day two (25 May) and quiet levels on day three (26 May). III. Event probabilities 24 May-26 May Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 23 May 073 Predicted 24 May-26 May 074/075/075 90 Day Mean 23 May 069 V. Geomagnetic A Indices Observed Afr/Ap 22 May 055/006 Estimated Afr/Ap 23 May 010/012 Predicted Afr/Ap 24 May-26 May 008/010-008/008-005/005 VI. Geomagnetic Activity Probabilities 24 May-26 May A. Middle Latitudes Active 30/25/15 Minor Storm 10/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/30/20 Major-severe storm 40/30/20