:Product: 1217RSGA.txt :Issued: 2009 Dec 17 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 351 Issued at 2200Z on 17 Dec 2009 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been low. One C-class event occurred from Region 1035 (N30W32), a C1/Sf at 16/2149Z. There were numerous B-class events throughout the period. Region 1035 has grown in area to approximately 210 millionths. However, the region has lost its delta magnetic configuration and is now a beta. IB. Solar Activity Forecast: Solar activity is expected to be low. There is a slight chance for an isolated M-class event from Region 1035. IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been quiet. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet during days 1-2 (18-19 December). An increase to unsettled to active levels is expected on day three (20 December). The increase is forecast due to the expected arrival of the CME observed on 16 December. III. Event Probabilities 18 Dec-20 Dec Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 17 Dec 087 Predicted 18 Dec-20 Dec 088/088/088 90 Day Mean 17 Dec 073 V. Geomagnetic A Indices Observed Afr/Ap 16 Dec 002/003 Estimated Afr/Ap 17 Dec 002/002 Predicted Afr/Ap 18 Dec-20 Dec 005/005-005/006-015/015 VI. Geomagnetic Activity Probabilities 18 Dec-20 Dec A. Middle Latitudes Active 05/15/45 Minor storm 01/05/15 Major-severe storm 01/01/05 B. High Latitudes Active 05/20/50 Minor storm 01/10/20 Major-severe storm 01/01/10