:Product: 20011231RSGA.txt :Issued: 2001 Dec 31 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 365 Issued at 2200Z on 31 Dec 2001 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity was at low levels. Region 9754 (S08W42) produced the largest flare of the period, an impulsive C6/1f flare at 31/1845 UTC. Region 9767 (S23E60) was the only other source of optically correlated flare activity during the period, producing small C-class flares. This region appears to have fully rotated onto the visible disk doubling reported arial spot coverage from yesterday's analysis. Other regions on the disk were mostly placid throughout the period. IB. Solar Activity Forecast: Solar activity is expected to be at moderate levels. Regions 9767, 9754, and 9751 (S08W42) all have the potential to produce M-class flares. IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field was at quiet to unsettled levels. The greater than 10 MeV proton event that began on 30/0245 UTC remains in progress and reached a maximum of 108 pfu at 31/1620 UTC. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels. A slight chance of active conditions exist on day one with the potential for a weak shock passage from the west limb CME of 29 December. The greater than 10 MeV event is expected to end late on day one of the forecast period. III. Event Probabilities 01 Jan-03 Jan Class M 75/75/75 Class X 15/15/15 Proton 99/50/10 PCAF in progress IV. Penticton 10.7 cm Flux Observed 31 Dec 246 Predicted 01 Jan-03 Jan 245/240/240 90 Day Mean 31 Dec 219 V. Geomagnetic A Indices Observed Afr/Ap 30 Dec 015/017 Estimated Afr/Ap 31 Dec 008/012 Predicted Afr/Ap 01 Jan-03 Jan 015/015-010/010-008/008 VI. Geomagnetic Activity Probabilities 01 Jan-03 Jan A. Middle Latitudes Active 25/20/15 Minor storm 10/05/05 Major-severe storm 05/01/01 B. High Latitudes Active 30/25/20 Minor storm 15/10/05 Major-severe storm 10/05/01