:Product: 0525RSGA.txt :Issued: 2013 May 25 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 145 Issued at 2200Z on 25 May 2013 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: 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 25/1049Z from Region 1755 (N11E12). There are currently 6 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 (26 May, 27 May, 28 May). IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at unsettled to minor storm levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 725 km/s at 25/2100Z. Total IMF reached 13 nT at 25/2040Z. The maximum southward component of Bz reached -11 nT at 25/2048Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 16 pfu at 24/2110Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 943 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (26 May) and quiet to unsettled levels on days two and three (27 May, 28 May). III. Event probabilities 26 May-28 May Class M 25/25/25 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 25 May 121 Predicted 26 May-28 May 120/120/125 90 Day Mean 25 May 123 V. Geomagnetic A Indices Observed Afr/Ap 24 May 017/023 Estimated Afr/Ap 25 May 020/029 Predicted Afr/Ap 26 May-28 May 015/020-010/010-007/008 VI. Geomagnetic Activity Probabilities 26 May-28 May A. Middle Latitudes Active 35/20/10 Minor Storm 15/05/01 Major-severe storm 05/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/25/20 Major-severe storm 50/25/20