:Product: 0911RSGA.txt :Issued: 2012 Sep 11 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 255 Issued at 2200Z on 11 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity was at low levels. Region 1564 (S11W82) was the most active region with several C-class flares, the largest of which was a C6/Sf at 10/2356Z. Regions 1567 (N16W02) and 1569 (S12E53) also contributed to the C-class flare activity. Region 1567 decayed throughout the period. There was no Earth directed CME activity during the period. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for an isolated M-class flare for the first day (12 September). M-class probability is expected to decrease for the second and third days (13-14 September) as Region 1564 rotates out of view. IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: Geomagnetic field activity was at quiet levels throughout the period. IIB. Geophysical Activity Forecast: Geomagnetic activity is expected to be quiet with a slight chance for unsettled levels on days 1 and 2 (12-13 September). An increase to quiet to unsettled levels with a slight chance for an active period is expected on the third day (14 September) due to a favorably positioned coronal hole. III. Event Probabilities 12 Sep-14 Sep Class M 20/10/05 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 11 Sep 105 Predicted 12 Sep-14 Sep 105/100/095 90 Day Mean 11 Sep 124 V. Geomagnetic A Indices Observed Afr/Ap 10 Sep 004/004 Estimated Afr/Ap 11 Sep 003/004 Predicted Afr/Ap 12 Sep-14 Sep 004/005-004/005-007/007 VI. Geomagnetic Activity Probabilities 12 Sep-14 Sep 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 15/15/15 Major-severe storm 10/05/10