:Product: 1223RSGA.txt :Issued: 2011 Dec 23 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 357 Issued at 2200Z on 23 Dec 2011 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity was low. The largest of the three C-class flares observed during the period was a C3 from Region 1376 (N16W84) as it prepared to rotate off the visible disk. Rotating onto the disk was new Region 1386 (S16E72), an Hsx type group with alpha magnetic characteristics. The remaining regions were magnetically simple and quiescent. IB. Solar Activity Forecast: Solar activity is expected to remain low with a slight chance for an M-class flare. IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field was at quiet levels. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain at mostly quiet levels for the next three days (24-26 December). III. Event Probabilities 24 Dec-26 Dec Class M 10/05/05 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 23 Dec 138 Predicted 24 Dec-26 Dec 140/140/140 90 Day Mean 23 Dec 144 V. Geomagnetic A Indices Observed Afr/Ap 22 Dec 004/002 Estimated Afr/Ap 23 Dec 000/001 Predicted Afr/Ap 24 Dec-26 Dec 006/005-006/005-006/005 VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec A. Middle Latitudes Active 05/05/10 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor storm 10/10/20 Major-severe storm 05/05/10