:Product: 0805RSGA.txt :Issued: 2011 Aug 05 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 Report of Solar and Geophysical Activity SDF Number 217 Issued at 2200Z on 05 Aug 2011 IA. Analysis of Solar Active Regions and Activity from 04/2100Z to 05/2100Z: Solar activity was low. Only low level C-flares were observed. Region 1261 (N14W64) was the major producer for C-flare activity. Region 1261 has decayed greatly in area and is now classified a Dsi spot class with a Beta-Gamma magnetic configuration. Region 1263 (N16W31) has remained largely unchanged and maintains a Beta-Gamma-Delta magnetic configuration. New Region 1267 (S17E26) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-flares from Regions 1261 or 1263. IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z: The geomagnetic field began the period at unsettled levels from 04/2100-05/0300Z. Quiet levels prevailed until after 1800Z. From 1800-2100Z, minor to severe storm levels dominated. Solar wind data from ACE showed a shock-like feature passing ACE at 04/2105Z which was followed by a 20 nT sudden impulse at 04/2155Z. The solar phi angle showed rotation from negative to positive between 0300-1400Z. An additional shock passage was seen at ACE at 1722Z followed by a noticeable increase in solar wind density, velocity and magnetic field. An additional enhancement in the solar wind parameters was observed at 1834Z which include Bz fluctuation to -20 nT. Although the interpretation is not yet certain, timing analysis and model simulation suggest that the 1722Z & 1834Z enhancements are the first two of the three expected CME passages. GOES 15 observed magnetopause crossings between 1900Z-1915Z and 2000Z-2030Z. GOES 13 also observed magnetopause crossings between 2000Z-2030Z. The greater than 10 MeV proton event that began at 04/0635Z reached a peak of 83 PFU at 05/1755Z and continues in progress. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to reach minor to major storm levels with a chance for severe storm periods on 06 August. Heightened activity is expected due to continued effects from the CMEs of 02, 03, and 04 August. Activity is expected to decrease to unsettled to active levels on 07 August. Quiet to unsettled conditions are expected on 08 August. III. Event Probabilities 06 Aug-08 Aug Class M 40/40/35 Class X 10/10/05 Proton 95/50/25 PCAF red IV. Penticton 10.7 cm Flux Observed 05 Aug 109 Predicted 06 Aug-08 Aug 110/110/100 90 Day Mean 05 Aug 096 V. Geomagnetic A Indices Observed Afr/Ap 04 Aug 003/004 Estimated Afr/Ap 05 Aug 020/020 Predicted Afr/Ap 06 Aug-08 Aug 035/035-015/018-008/010 VI. Geomagnetic Activity Probabilities 06 Aug-08 Aug A. Middle Latitudes Active 20/25/10 Minor storm 40/15/05 Major-severe storm 35/05/00 B. High Latitudes Active 20/25/15 Minor storm 35/20/05 Major-severe storm 40/15/00