:Product: 0812RSGA.txt :Issued: 2011 Aug 12 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 224 Issued at 2200Z on 12 Aug 2011 IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity was very low. Todays largest event was a B6 at 11/2309Z which appeared to originate from Region 1263 (N17, L=296, about a day beyond west limb at the time of the event). The solar disk now consists of only two spotted regions, Region 1269 (S22E03) and Region 1270 (N23E41). Both groups are very small and only possess spots without penumbra. A filament eruption in the northeast quadrant and associated CME were observed, beginning at about 0336Z. The CME appears to be travelling well out of the ecliptic plane and is not likely to be geoeffective. IB. Solar Activity Forecast: Solar activity is expected to be very low for the next three days. IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field was quiet during the past 24 hours. Solar wind observations of the Phi angle from the ACE spacecraft appeared to indicate a transition to a negative polarity sector. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels throughout the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be predominantly quiet for day 1 (13 August). An increase to unsettled levels with a chance for active periods is expected for days 2 and 3 (14-15 August) as a co-rotating interaction region followed by a negative polarity coronal hole high speed stream are expected to become weakly geoeffective. III. Event Probabilities 13 Aug-15 Aug Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 12 Aug 083 Predicted 13 Aug-15 Aug 082/082/080 90 Day Mean 12 Aug 096 V. Geomagnetic A Indices Observed Afr/Ap 11 Aug 003/006 Estimated Afr/Ap 12 Aug 007/007 Predicted Afr/Ap 13 Aug-15 Aug 007/007-012/012-010/010 VI. Geomagnetic Activity Probabilities 13 Aug-15 Aug A. Middle Latitudes Active 25/40/30 Minor storm 05/10/10 Major-severe storm 01/01/01 B. High Latitudes Active 25/40/35 Minor storm 10/15/15 Major-severe storm 01/05/05