:Product: 0803RSGA.txt :Issued: 2011 Aug 03 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 215 Issued at 2200Z on 03 Aug 2011 IA. Analysis of Solar Active Regions and Activity from 02/2100Z to 03/2100Z: Solar activity was high. Region 1261 (N16W37) produced the largest event of the period, an M6/2B flare at 03/1348Z. It was accompanied by a 10cm radio burst (180 sfu), Type II (812 km/s) and IV emissions. A CME was subsequently observed in STEREO-A COR2 imagery at 03/1409Z. Time-height extrapolation from LASCO C3 imagery indicated a speed of 624 km/s. Region 1263 (N17W06) also produced an M1/1F flare at 03/0432Z. Both regions were classified as Dki type spot groups with beta-gamma and beta-gamma-delta magnetic characteristics respectively. A weak CME was also observed in STEREO-A COR2 imagery at approximately 03/0109Z but was not expected to be geoeffective. IB. Solar Activity Forecast: Solar activity is likely to remain moderate to high for the next three days (04-06 Aug) under the continued threat of a major event. Regions 1261 and 1263 are most likely to produce activity. IIA. Geophysical Activity Summary 02/2100Z to 03/2100Z: The geomagnetic field was predominantly quiet. Wind speeds at the ACE spacecraft were near 360 km/s and Bz was near zero. A slight enhancement in 10 MeV protons was observed at both ACE and the GOES-13 satellite, but remained below alert thresholds. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly quiet on day 1 (04 Aug), becoming active on days 2 and 3 (05-06 Aug), with a slight chance of minor to major storms at high latitudes. The increased geomagnetic activity is associated with the arrivals of CMEs from 02 and 03 August. The 10 MeV protons are likely to exceed the 10 pfu threshold with CME passage. III. Event Probabilities 04 Aug-06 Aug Class M 65/65/60 Class X 10/10/10 Proton 15/55/55 PCAF green IV. Penticton 10.7 cm Flux Observed 03 Aug 120 Predicted 04 Aug-06 Aug 120/120/115 90 Day Mean 03 Aug 096 V. Geomagnetic A Indices Observed Afr/Ap 02 Aug 003/003 Estimated Afr/Ap 03 Aug 003/003 Predicted Afr/Ap 04 Aug-06 Aug 005/005-020/025-018/020 VI. Geomagnetic Activity Probabilities 04 Aug-06 Aug A. Middle Latitudes Active 05/40/25 Minor storm 01/10/05 Major-severe storm 01/05/01 B. High Latitudes Active 05/40/40 Minor storm 01/15/15 Major-severe storm 01/05/05