:Product: 0531RSGA.txt :Issued: 2013 May 31 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 151 Issued at 2200Z on 31 May 2013 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was an M1 event observed at 31/2000Z from Region 1760 (N12E38). There are currently 5 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 and a slight chance for an M-class flare on days one, two, and three (01 Jun, 02 Jun, 03 Jun). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 423 km/s at 31/1943Z. Total IMF reached 9 nT at 31/1852Z. The maximum southward component of Bz reached -8 nT at 31/1710Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 32295 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (01 Jun), quiet to active levels on day two (02 Jun) and quiet to unsettled levels on day three (03 Jun). III. Event probabilities 01 Jun-03 Jun Class M 15/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 31 May 102 Predicted 01 Jun-03 Jun 100/100/110 90 Day Mean 31 May 123 V. Geomagnetic A Indices Observed Afr/Ap 30 May 002/003 Estimated Afr/Ap 31 May 005/006 Predicted Afr/Ap 01 Jun-03 Jun 011/018-012/015-010/010 VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun A. Middle Latitudes Active 25/30/20 Minor Storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/30/25 Major-severe storm 40/40/30