:Product: 0822RSGA.txt :Issued: 2013 Aug 22 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 234 Issued at 2200Z on 22 Aug 2013 IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4 event observed at 22/0506Z from Region 1820 (S12W61). 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 days one, two, and three (23 Aug, 24 Aug, 25 Aug). IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: 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 610 km/s at 22/0712Z. Total IMF reached 9 nT at 22/0329Z. The maximum southward component of Bz reached -6 nT at 22/0411Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 752 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (23 Aug), unsettled to minor storm levels on day two (24 Aug) and quiet to minor storm levels on day three (25 Aug). III. Event probabilities 23 Aug-25 Aug Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 22 Aug 132 Predicted 23 Aug-25 Aug 130/125/120 90 Day Mean 22 Aug 113 V. Geomagnetic A Indices Observed Afr/Ap 21 Aug 013/020 Estimated Afr/Ap 22 Aug 010/012 Predicted Afr/Ap 23 Aug-25 Aug 012/015-020/025-019/020 VI. Geomagnetic Activity Probabilities 23 Aug-25 Aug A. Middle Latitudes Active 30/40/40 Minor Storm 10/25/30 Major-severe storm 01/05/10 B. High Latitudes Active 15/10/05 Minor Storm 30/25/20 Major-severe storm 45/60/75