:Product: 0813RSGA.txt :Issued: 2013 Aug 13 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 225 Issued at 2200Z on 13 Aug 2013 IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: 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 13/1850Z from Region 1809 (N14W0*). There are currently 5 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 (14 Aug, 15 Aug, 16 Aug). IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: 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 437 km/s at 13/1935Z. Total IMF reached 10 nT at 13/1803Z. The maximum southward component of Bz reached -8 nT at 13/1518Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 661 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (14 Aug), quiet to active levels on day two (15 Aug) and quiet to unsettled levels on day three (16 Aug). III. Event probabilities 14 Aug-16 Aug Class M 30/30/30 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 13 Aug 122 Predicted 14 Aug-16 Aug 120/120/125 90 Day Mean 13 Aug 114 V. Geomagnetic A Indices Observed Afr/Ap 12 Aug 006/005 Estimated Afr/Ap 13 Aug 005/006 Predicted Afr/Ap 14 Aug-16 Aug 015/018-012/015-010/010 VI. Geomagnetic Activity Probabilities 14 Aug-16 Aug A. Middle Latitudes Active 30/30/15 Minor Storm 15/15/05 Major-severe storm 01/05/01 B. High Latitudes Active 15/15/15 Minor Storm 35/30/25 Major-severe storm 40/50/25