:Product: 0221RSGA.txt :Issued: 2011 Feb 21 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 052 Issued at 2200Z on 21 Feb 2011 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been low. Region 1161 (N11W42) produced multiple C-class events and remains an E-type sunspot group with a beta-gamma magnetic classification, while Region 1162 (N17W46) remained stable and quiet. The periods largest x-ray event a C7 at 21/1012Z came from Region 1158 which has rotated off the visible disk. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate with a slight chance for an X-class event from Region 1161 for the next three days (22-24 February). IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been quiet to unsettled during the past 24 hours. Solar wind data from the ACE spacecraft indicated a slight drop in velocity to around 380 km/s and sustained negative Bz of -4nT during the period. 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 a slight chance for isolated active periods during the next three days (22-24 February). III. Event Probabilities 22 Feb-24 Feb Class M 50/50/50 Class X 10/10/10 Proton 05/05/05 PCAF Green IV. Penticton 10.7 cm Flux Observed 21 Feb 097 Predicted 22 Feb-24 Feb 098/098/095 90 Day Mean 21 Feb 086 V. Geomagnetic A Indices Observed Afr/Ap 20 Feb 006/007 Estimated Afr/Ap 21 Feb 007/008 Predicted Afr/Ap 22 Feb-24 Feb 007/008-007/008-007/008 VI. Geomagnetic Activity Probabilities 22 Feb-24 Feb A. Middle Latitudes Active 10/10/10 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor storm 10/10/10 Major-severe storm 01/01/01