:Product: 0912RSGA.txt :Issued: 2011 Sep 12 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 12 Sep 2011 IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity was low during the past 24 hours. Region 1292 (N08E52) produced two C-class flares, the largest a C2 at 12/0329Z. Regions 1293 (N17W11), 1294 (S18E27), and 1295 (N21E72) were numbered today. Region 1295 produced a C9 at 12/2054Z. The region is considered an H-type group but is still rotating around the limb. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for isolated M-class events for the next three days (13-15 September). IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been unsettled to active during the past 24 hours due to effects from a favorably positioned coronal hole high speed stream (CH HSS). The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled with isolated active periods for days one and two (13-14 September) due to effects from a CH HSS. Mostly quiet conditions are expected on day three (15 September) as CH HSS effects subside. III. Event Probabilities 13 Sep-15 Sep Class M 30/30/30 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 12 Sep 124 Predicted 13 Sep-15 Sep 120/120/115 90 Day Mean 12 Sep 100 V. Geomagnetic A Indices Observed Afr/Ap 11 Sep 008/009 Estimated Afr/Ap 12 Sep 018/028 Predicted Afr/Ap 13 Sep-15 Sep 010/012-008/008-005/005 VI. Geomagnetic Activity Probabilities 13 Sep-15 Sep A. Middle Latitudes Active 15/15/05 Minor storm 05/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/05 Minor storm 05/01/01 Major-severe storm 01/01/01