:Product: 0816RSGA.txt :Issued: 2013 Aug 16 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 228 Issued at 2200Z on 16 Aug 2013 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: 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 15/2216Z from Region 1817 (S21W44). 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 (17 Aug, 18 Aug, 19 Aug). IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 860 km/s at 16/1145Z. Total IMF reached 9 nT at 15/2349Z. The maximum southward component of Bz reached -8 nT at 16/0244Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1355 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (17 Aug) and quiet to unsettled levels on days two and three (18 Aug, 19 Aug). III. Event probabilities 17 Aug-19 Aug Class M 35/35/35 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 16 Aug 120 Predicted 17 Aug-19 Aug 125/130/130 90 Day Mean 16 Aug 114 V. Geomagnetic A Indices Observed Afr/Ap 15 Aug 015/016 Estimated Afr/Ap 16 Aug 017/023 Predicted Afr/Ap 17 Aug-19 Aug 012/015-011/012-008/005 VI. Geomagnetic Activity Probabilities 17 Aug-19 Aug A. Middle Latitudes Active 45/20/10 Minor Storm 10/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/20 Minor Storm 30/30/30 Major-severe storm 50/30/15