:Product: 0823RSGA.txt :Issued: 2013 Aug 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 235 Issued at 2200Z on 23 Aug 2013 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 C1 event observed at 22/2207Z from Region 1828 (N14E26). There are currently 9 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on day one (24 Aug) and expected to be low on days two and three (25 Aug, 26 Aug). IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 593 km/s at 22/2215Z. Total IMF reached 7 nT at 22/2100Z. The maximum southward component of Bz reached -5 nT at 22/2205Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1857 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (24 Aug), quiet to minor storm levels on day two (25 Aug) and quiet to unsettled levels on day three (26 Aug). III. Event probabilities 24 Aug-26 Aug Class M 10/05/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Aug 124 Predicted 24 Aug-26 Aug 125/120/115 90 Day Mean 23 Aug 113 V. Geomagnetic A Indices Observed Afr/Ap 22 Aug 011/014 Estimated Afr/Ap 23 Aug 014/016 Predicted Afr/Ap 24 Aug-26 Aug 020/025-019/020-011/012 VI. Geomagnetic Activity Probabilities 24 Aug-26 Aug A. Middle Latitudes Active 40/40/20 Minor Storm 25/30/05 Major-severe storm 05/10/01 B. High Latitudes Active 10/05/15 Minor Storm 25/20/30 Major-severe storm 60/75/30