:Product: 1023RSGA.txt :Issued: 2011 Oct 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 296 Issued at 2200Z on 23 Oct 2011 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity was low. Region 1324 (N12W00) produced a C2 X-ray flare at 23/1147Z as well as a few other optical subflares. The region continues to slowly decay. New Region 1331 (N11W60) emerged on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an isolated M-class flare. Regions 1324 (N12W00) and 1330 (N08E60) are the most likely source of flare activity. IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field was quiet. A greater than 10 MeV proton event began at 23/1500Z. So far the observed peak flux was 13 pfu at 23/1535Z. The source of the event is believed to be yesterdays long-duration M1 flare at 22/1110Z in Region 1314 (N29, L=053). IIB. Geophysical Activity Forecast: The geomagnetic field is expected be mostly quiet becoming quiet to unsettled with a chance of active periods on 25 October. This activity is expected in response to the arrival of a CME that occurred at 22/0058Z in association with an eruptive filament. The greater than 10 MeV proton event is expected to end by 24 October. III. Event Probabilities 24 Oct-26 Oct Class M 20/20/20 Class X 01/01/01 Proton 10/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 23 Oct 156 Predicted 24 Oct-26 Oct 150/145/140 90 Day Mean 23 Oct 122 V. Geomagnetic A Indices Observed Afr/Ap 22 Oct 002/003 Estimated Afr/Ap 23 Oct 002/004 Predicted Afr/Ap 24 Oct-26 Oct 005/005-010/010-010/010 VI. Geomagnetic Activity Probabilities 24 Oct-26 Oct A. Middle Latitudes Active 05/30/30 Minor storm 01/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 10/40/40 Minor storm 05/10/10 Major-severe storm 01/01/01