:Product: 0923RSGA.txt :Issued: 2011 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 266 Issued at 2200Z on 23 Sep 2011 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity was moderate. An M1/1n flare was observed at 23/0159Z from Region 1295 (N25W74) along with several C-class flares, including an long-duration flare at 23/0850Z. Region 1302 (N13E58) remains the most significant region on the disk as an Eki Beta-Gamma with an area of 780 millionths. IB. Solar Activity Forecast: Solar activity is expected to be high, with a slight chance for another X-class flare from Region 1302. IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field was quiet. The 10 MeV protons at geosynchronous orbit are expected to exceed the 10 pfu threshold during the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet on day one (24 September). Quiet, with isolated unsettled levels, are expected on day two (25 September), due to a weak coronal hole high-speed stream. Quiet levels are expected on day three (26 September). III. Event Probabilities 24 Sep-26 Sep Class M 70/70/70 Class X 20/20/20 Proton 90/80/50 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Sep 158 Predicted 24 Sep-26 Sep 160/165/170 90 Day Mean 23 Sep 106 V. Geomagnetic A Indices Observed Afr/Ap 22 Sep 002/003 Estimated Afr/Ap 23 Sep 002/004 Predicted Afr/Ap 24 Sep-26 Sep 005/005-007/008-005/005 VI. Geomagnetic Activity Probabilities 24 Sep-26 Sep A. Middle Latitudes Active 05/10/05 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/10 Minor storm 01/01/01 Major-severe storm 01/01/01