:Product: 20030810RSGA.txt :Issued: 2003 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 222 Issued at 2200Z on 10 Aug 2003 IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity was low. Region 425 (S09W43) produced a C3/Sf flare at 10/1020Z followed by a more gradual C2 flare that peaked at 10/1128Z. Region 431 (S13E56) produced an impulsive C1/Sf flare at 10/0127Z. This beta gamma region is showing some minor complexity in a spot group with over 250 millionths of white light coverage. Region 424 (S18W41), the largest region on the visible disk, exhibited only minor plage fluctuations this period. Remaining active regions were quiet. IB. Solar Activity Forecast: Solar activity is expected to continue at low levels. C-class flares are possible from Regions 424, 425, and 431. IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field was quiet to active. A declining high speed stream with very low density and weak northward IMF Bz continues to buffet the Earth's magnetic field. Solar wind speed declined from near 700 km/s to below 600 km/s by the end of the period. The greater than 2 MeV electrons at geosynchronous orbit reached high levels again today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly quiet to active on day one. Another coronal hole high speed stream is expected to impact the geomagnetic field on days two and three. Expect unsettled to minor storm levels both days with isolated major storm periods on day three. III. Event Probabilities 11 Aug-13 Aug Class M 20/20/20 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 10 Aug 131 Predicted 11 Aug-13 Aug 130/130/125 90 Day Mean 10 Aug 125 V. Geomagnetic A Indices Observed Afr/Ap 09 Aug 010/015 Estimated Afr/Ap 10 Aug 010/014 Predicted Afr/Ap 11 Aug-13 Aug 012/012-020/020-020/035 VI. Geomagnetic Activity Probabilities 11 Aug-13 Aug A. Middle Latitudes Active 30/40/45 Minor storm 10/20/25 Major-severe storm 01/05/05 B. High Latitudes Active 35/45/50 Minor storm 15/30/35 Major-severe storm 05/10/15