:Product: 0828RSGA.txt :Issued: 2005 Aug 28 2204 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Environment Center and the U.S. Air Force. # Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 240 Issued at 2200Z on 28 Aug 2005 IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity increased to moderate levels today. Region 803 (N11E27) produced the largest flare of the period, an impulsive M1/Sf event that occurred at 28/1028Z. This region underwent some decay of penumbral coverage during the period with a delta structure materializing in the leading portion of this reversed polarity spot group. A disappearing solar filament was reported in the southwest solar quadrant, occurring between 28/0755 and 0946Z. The remaining spotted groups were quiescent over the past 24 hours. No new regions were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at low levels. Region 803 is capable of producing further isolated M-class flare activity. IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field was at predominantly quiet levels. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominantly quiet to unsettled levels for 29-31 August. III. Event Probabilities 29 Aug-31 Aug Class M 30/30/30 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 28 Aug 090 Predicted 29 Aug-31 Aug 090/085/085 90 Day Mean 28 Aug 093 V. Geomagnetic A Indices Observed Afr/Ap 27 Aug 004/007 Estimated Afr/Ap 28 Aug 004/006 Predicted Afr/Ap 29 Aug-31 Aug 005/008-005/008-005/012 VI. Geomagnetic Activity Probabilities 29 Aug-31 Aug A. Middle Latitudes Active 15/15/15 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/20 Minor storm 05/05/10 Major-severe storm 01/01/05