:Product: 0923RSGA.txt :Issued: 2012 Sep 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 267 Issued at 2200Z on 23 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity was at low levels. The largest event of the period was a long duration C1 x-ray flare at 23/1556Z from an area of enhanced emission located behind the east limb. Region 1577 (N08E30) indicated the most change during the period developing numerous intermediate spots. The remaining regions were quiet and stable. No Earth-directed CMEs were observed. IB. Solar Activity Forecast: Solar activity is expected to be at low levels with a slight chance for M-class activity all three days of the forecast period (24 - 26 September) as active regions are expected to rotate onto the visible disk. IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field was at quiet levels. ACE satellite measurements indicated a steady decline in wind speed from about 400 km/s to near 350 km/s while the Bz component of the interplanetary magnetic field did not vary much beyond +/- 4 nT. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominately quiet levels all three days of the forecast period (24 - 26 September). III. Event Probabilities 24 Sep-26 Sep Class M 10/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Sep 134 Predicted 24 Sep-26 Sep 135/140/145 90 Day Mean 23 Sep 123 V. Geomagnetic A Indices Observed Afr/Ap 22 Sep 003/006 Estimated Afr/Ap 23 Sep 002/003 Predicted Afr/Ap 24 Sep-26 Sep 004/005-005/005-004/005 VI. Geomagnetic Activity Probabilities 24 Sep-26 Sep A. Middle Latitudes Active 05/05/05 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 10/10/10 Minor storm 01/01/01 Major-severe storm 01/01/01