:Product: 20011121RSGA.txt :Issued: 2001 Nov 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 325 Issued at 2200Z on 21 Nov 2001 **********CORRECTED COPY********** IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been low. Region 9704 (S17W24) was the sole source of all the optical activity, and remains the largest and most magnetically complex region on the visible disk. The largest event of the period was a C6/Sf at 21/1818 UTC. A more significant, long duration C4/Sf occurred during 21/1207-1650 UTC, with peak flux observed at 21/1458 UTC. This event was accompanied by a Type-IV radio sweep, and an associated filament eruption at approximately N35W10. By 21/1406 UTC, a full halo CME was evident in SOHO/LASCO imagery. New Region 9712 (N13E71) was numbered today as it rotated into view on the east limb. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. 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 through 23 November. A shock arrival is expected early on 24 November, in association with the CME activity described in section 1A above. Geomagnetic field activity is expected to increase on that date, with isolated minor storm periods possible. III. Event Probabilities 22 Nov-24 Nov Class M 35/35/35 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Nov 184 Predicted 22 Nov-24 Nov 175/175/170 90 Day Mean 21 Nov 218 V. Geomagnetic A Indices Observed Afr/Ap 20 Nov 008/008 Estimated Afr/Ap 21 Nov 006/008 Predicted Afr/Ap 22 Nov-24 Nov 008/008-010/010-018/020 VI. Geomagnetic Activity Probabilities 22 Nov-24 Nov A. Middle Latitudes Active 15/15/25 Minor storm 05/05/10 Major-severe storm 01/01/05 B. High Latitudes Active 20/20/35 Minor storm 05/10/15 Major-severe storm 01/01/10