:Product: 20011104RSGA.txt :Issued: 2001 Nov 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 308 Issued at 2200Z on 04 Nov 2001 IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity has been high. Region 9684 (N06W27) produced an X1/3b flare beginning at 1603 UTC, maximum at 1620 UTC, and ending at 1647 UTC. The event was accompanied by strong radio bursts, a type II sweep, and a type IV sweep. A CME was observed to enter the C2 field of view during the flare, with the leading edge just visible at 1635 UTC. The front edge moved quickly across C2 and exited somewhere between 1655 UTC and 1705 UTC. Region 9684 has grown and the leader and trailer spots merged during the past 24 hours, making the region a beta-gamma-delta group. Region 9687 (S20E35) continues to be a complex, beta-gamma group and produced a few C-class subflares. Region 9682 (N13W64) is still the largest group on the disk but could only muster a couple of subflares. A 10 degree filament just west of Region 9684 disappeared sometime between 03/2208 UTC and 04/0629 UTC. IB. Solar Activity Forecast: Solar activity is expected to be moderate to high. M-class events are likely to occur during the next three days. There is a fair chance for an additional major flare from Region 9684, especially if new magnetic flux continues to emerge. Regions 9682 and 9687 also continue to pose a slight threat for major flare activity. IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic field was quiet to unsettled during the past 24 hours. A greater than 100 MeV proton event began at 1650 UTC, shortly after today's X-class flare. Flux levels rose quickly initially, but began to level off around 1800 UTC, although they are still climbing slowly. The maximum 100 MeV flux observed so far is 56 pfu at 2035 UTC. A greater than 10 MeV proton event began at 1705 UTC. This event also seems to be leveling off, and the maximum flux observed so far is 1180 pfu at 2040 UTC. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to slightly active tomorrow. Major storm conditions are likely to follow the arrival of a shock from today's solar event, sometime early on the 2nd day (06 November). The disturbance is expected to last for about 24 hours, and a decrease to mostly active conditions should occur on the third day. Today's greater than 100 MeV proton event is expected to continue for the next 12 hours. The greater than 10 MeV proton event should continue tomorrow, and is likely to get an enhancement of flux levels on the second day with the arrival of the interplanetary shock from today's solar event. III. Event Probabilities 05 Nov-07 Nov Class M 80/80/80 Class X 25/25/25 Proton 99/80/25 PCAF in progress IV. Penticton 10.7 cm Flux Observed 04 Nov 227 Predicted 05 Nov-07 Nov 220/215/210 90 Day Mean 04 Nov 206 V. Geomagnetic A Indices Observed Afr/Ap 03 Nov 001/003 Estimated Afr/Ap 04 Nov 007/008 Predicted Afr/Ap 05 Nov-07 Nov 015/015-050/050-025/025 VI. Geomagnetic Activity Probabilities 05 Nov-07 Nov A. Middle Latitudes Active 25/10/20 Minor storm 15/15/35 Major-severe storm 15/75/35 B. High Latitudes Active 25/05/15 Minor storm 15/10/30 Major-severe storm 15/80/35