NOAA SEC Report of Solar-Geophysical Activity 21 Dec 2000
:Product: Report of Solar-Geophysical Activity :Issued: 2000 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 356 Issued at 2200Z on 21 Dec 2000 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity remained low. Region 9280 (N08E48) produced frequent low-level C-class subflares. This region possessed a modest degree of magnetic complexity and showed a minor increase in spot count and penumbral coverage. The remaining regions were stable and simply structured. New Region 9282 (N19E68) was numbered. IB. Solar Activity Forecast: Solar activity is expected to be mostly low with a slight chance for an isolated M-class flare from Region 9280. IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: Geomagnetic field activity was at quiet to unsettled levels. A weak interplanetary shock passed the ACE spacecraft at around 21/1100 UTC, presumably from the halo-CME observed on 18 December. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at quiet to unsettled levels during most of the period. Intermittent active periods will be possible during 23 - 24 December due to coronal hole effects. III. Event Probabilities 22 Dec-24 Dec Class M 35/35/35 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Dec 195 Predicted 22 Dec-24 Dec 195/195/190 90 Day Mean 21 Dec 175 V. Geomagnetic A Indices Observed Afr/Ap 20 Dec 002/004 Estimated Afr/Ap 21 Dec 006/008 Predicted Afr/Ap 22 Dec-24 Dec 012/012-015/015-015/015 VI. Geomagnetic Activity Probabilities 22 Dec-24 Dec A. Middle Latitudes Active 25/35/35 Minor storm 10/20/20 Major-severe storm 01/05/05 B. High Latitudes Active 30/40/40 Minor storm 15/25/25 Major-severe storm 01/05/05
