:Product: 20010804RSGA.txt :Issued: 2001 Aug 04 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 216 Issued at 2200Z on 04 Aug 2001 IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity was low. The largest event of the period was a C9 flare and CME on the SE limb. The associated active region is just now rotating into view. Region 9563 (N23E05) continues to grow and produced an impulsive C7/Sf at 04/0949Z. The most impressive development of the period was the growth in Region 9557 (S21W37). This region developed from an area of approximately 50 millionths of white light area yesterday to nearly 500 millionths today. The extensive development of the penumbral field appears to almost encompass the 20+ sunspots. Small C-class activity was also observed in Region 9566 (N17E22). IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. The chance for M-class activity has certainly increased with the development in Region 9557 and the activity on the SE limb. Region 9563, which produced an impulsive M1/Sn flare early on 3 July, still has good potential for a low M-class flare. IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field was quiet to unsettled. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to continue at quiet to unsettled levels. Isolated active periods are possible at higher latitudes. III. Event Probabilities 05 Aug-07 Aug Class M 50/50/50 Class X 10/10/10 Proton 10/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 04 Aug 148 Predicted 05 Aug-07 Aug 155/160/160 90 Day Mean 04 Aug 148 V. Geomagnetic A Indices Observed Afr/Ap 03 Aug 011/014 Estimated Afr/Ap 04 Aug 008/009 Predicted Afr/Ap 05 Aug-07 Aug 010/018-010/015-010/010 VI. Geomagnetic Activity Probabilities 05 Aug-07 Aug A. Middle Latitudes Active 25/25/25 Minor storm 15/15/15 Major-severe storm 01/01/01 B. High Latitudes Active 35/30/30 Minor storm 20/15/15 Major-severe storm 05/01/01