NOAA SEC Report of Solar-Geophysical Activity 21 December 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Dec 21 2200 UT # 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 355 Issued at 2200Z on 21 Dec 2001 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was low. Region 9742 (N10W03) is the largest and most active group on the visible disk and produced several minor C-class flares. This beta-gamma region continues to grow in spot count, area, and magnetic complexity, and now exceeds 700 millionths of white light area. No remarkable activity or developments were observed in the remaining active regions. New Regions 9750 (S16W64) and 9751 (N04E68) were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be moderate. Region 9742 has good potential for M-class flares and an isolated chance for a major flare. IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet to active. An increase in the solar wind speed began at around 21/1100Z. This increase was accompanied by sustained periods of southward Bz resulting in unsettled to active periods at all latitudes. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to continue at quiet to active levels. III. Event Probabilities 22 Dec-24 Dec Class M 60/60/60 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Dec 234 Predicted 22 Dec-24 Dec 240/240/240 90 Day Mean 21 Dec 218 V. Geomagnetic A Indices Observed Afr/Ap 20 Dec 002/005 Estimated Afr/Ap 21 Dec 010/010 Predicted Afr/Ap 22 Dec-24 Dec 012/010-010/010-008/012 VI. Geomagnetic Activity Probabilities 22 Dec-24 Dec A. Middle Latitudes Active 40/35/20 Minor storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 50/40/40 Minor storm 15/15/15 Major-severe storm 05/05/05
