:Product: 20040810RSGA.txt :Issued: 2004 Aug 10 2200 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 223 Issued at 2200Z on 10 Aug 2004 IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity was low. Today's activity consisted of occasional C-class flares from Region 656 (S12E18). Although the region is still growing the rate of growth has decreased significantly and the rate of flare activity has also decreased. The region continues to have a delta magnetic class but shearing in the region appears to have decreased slightly. New Region 659 (N18E59) was assigned today and is a small, stable H-type group. IB. Solar Activity Forecast: Solar activity is expected to be mostly low, but there is a fair chance for an isolated M-class flare from Region 656. There may be an increase in background and activity levels on 12 August with the return of old Region 652 (N08, L=348) which produced numerous M-class events on its previous disk transit. IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field ranged from quiet to active levels with a minor storm interval at some locations from 1500-1800 UTC. Solar wind observations show an increase of velocity and temperature, and a decrease of density, consistent with the onset of a high-speed coronal hole solar wind stream. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly unsettled with occasional active periods for the next three days (11-13 August). III. Event Probabilities 11 Aug-13 Aug Class M 40/40/40 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 10 Aug 121 Predicted 11 Aug-13 Aug 125/130/135 90 Day Mean 10 Aug 106 V. Geomagnetic A Indices Observed Afr/Ap 09 Aug 012/013 Estimated Afr/Ap 10 Aug 010/013 Predicted Afr/Ap 11 Aug-13 Aug 010/012-010/010-010/010 VI. Geomagnetic Activity Probabilities 11 Aug-13 Aug A. Middle Latitudes Active 30/30/30 Minor storm 20/20/20 Major-severe storm 05/05/05 B. High Latitudes Active 30/30/30 Minor storm 25/25/25 Major-severe storm 05/05/05