:Product: 20010921RSGA.txt :Issued: 2001 Sep 21 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 264 Issued at 2200Z on 21 Sep 2001 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was low. The largest flare of the past day was a C7/Sf at 21/0702 UTC in Region 9631 (N09W24). Regions 9620 (N11E04), 9628 (S18E38), and 9632 (S17E56) also produced C-class subflares. The largest, most magnetically complex sunspot groups appear to be 9628 and 9632. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. M-class activity is possible from a number of areas, including Regions 9620, 9628, and 9632. IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet to unsettled. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled. III. Event Probabilities 22 Sep-24 Sep Class M 80/80/80 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Sep 239 Predicted 22 Sep-24 Sep 245/250/250 90 Day Mean 21 Sep 165 V. Geomagnetic A Indices Observed Afr/Ap 20 Sep 007/005 Estimated Afr/Ap 21 Sep 006/009 Predicted Afr/Ap 22 Sep-24 Sep 010/015-010/012-010/010 VI. Geomagnetic Activity Probabilities 22 Sep-24 Sep A. Middle Latitudes Active 20/20/20 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 30/30/30 Minor storm 10/10/10 Major-severe storm 01/01/01