NOAA SEC Report of Solar-Geophysical Activity 20 Dec 2000
:Product: Report of Solar-Geophysical Activity :Issued: 2000 Dec 20 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 20 Dec 2000 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity remained at low levels. Regions 9272 (N14W59), 9278 (N09E23), and 9279 (S13E41) each produced isolated, low-level C-class subflares. No significant changes were observed in any of the sunspot groups. Region 9280 (N08E61), which was stable during the period, may possess a moderate degree of magnetic complexity (beta-gamma structure), but analysis was difficult due to limb proximity. New Region 9281 (N07E39) 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 Regions 9278 or 9280. IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: Geomagnetic field activity has been at quiet levels. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to increase to unsettled to active levels during the first two days of the period due to an expected CME passage. Quiet to unsettled levels are expected on the final day. III. Event Probabilities 21 Dec-23 Dec Class M 35/35/35 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Dec 201 Predicted 21 Dec-23 Dec 200/195/195 90 Day Mean 20 Dec 176 V. Geomagnetic A Indices Observed Afr/Ap 19 Dec 002/005 Estimated Afr/Ap 20 Dec 004/007 Predicted Afr/Ap 21 Dec-23 Dec 015/020-020/025-012/015 VI. Geomagnetic Activity Probabilities 21 Dec-23 Dec A. Middle Latitudes Active 25/35/20 Minor storm 15/20/10 Major-severe storm 10/10/01 B. High Latitudes Active 30/35/25 Minor storm 20/25/15 Major-severe storm 15/15/01
