:Product: 20011213RSGA.txt :Issued: 2001 Dec 13 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 347 Issued at 2200Z on 13 Dec 2001 IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity was high. Region 9733 (N14E04) produced an X6.2/3b flare at 13/1430 UTC. This event also produced associated Type II and IV radio sweeps and a partial-halo coronal mass ejection (CME). This region is continuing to grow more complex, developing a near horizontal inversion line in its trailing portions. Region 9727 (S21W66) was also quite active during the period, producing three M-class flares. Region 9727 showed continued growth in size and complexity during the period. Regions 9727 and 9733 both retain beta-gamma-delta magnetic classifications. Three new spot groups were numbered today: 9739 (S13W02), 9740 (S06E56), and 9741 (N07E72). IB. Solar Activity Forecast: Solar activity is expected to be at moderate to high levels with isolated M-class flares likely. There will also be a chance for a major flare from Regions 9727 or 9733. IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field was at mostly quiet levels, with an isolated unsettled period at 12/21-2400 UTC. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled conditions on the first day of the forecast period. The CME produced by the X6.2 flare should impact earth late on the second day. The impact is expected to produce active conditions on the second and third days. Imagery from the LASCO/SOHO spacecraft show that most of the CME is directed in a predominately Northerly direction, hence the expected effect on Earth should be significantly less than if the CME was more directly aimed toward Earth. III. Event Probabilities 14 Dec-16 Dec Class M 80/80/70 Class X 20/20/15 Proton 20/20/15 PCAF yellow IV. Penticton 10.7 cm Flux Observed 13 Dec 220 Predicted 14 Dec-16 Dec 220/220/210 90 Day Mean 13 Dec 218 V. Geomagnetic A Indices Observed Afr/Ap 12 Dec 008/012 Estimated Afr/Ap 13 Dec 006/007 Predicted Afr/Ap 14 Dec-16 Dec 012/015-020/020-025/025 VI. Geomagnetic Activity Probabilities 14 Dec-16 Dec A. Middle Latitudes Active 20/30/40 Minor storm 10/20/25 Major-severe storm 01/10/15 B. High Latitudes Active 25/40/45 Minor storm 15/25/30 Major-severe storm 05/10/10