:Product: 0519RSGA.txt :Issued: 2011 May 19 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 139 Issued at 2200Z on 19 May 2011 IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity was low during the past 24 hours. A long duration B3 event occurred in association with a filament eruption at 19/0436Z centered near N20W25. An associated CME became visible in LASCO C2 imagery at 19/0436Z but is not expected to cause significant activity at Earth. Region 1217 (S23W50) decayed to plage during the period. All other regions on the disk remained relatively quiet and stable. IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for isolated C-class events for the next three days (20-22 May). IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field was quiet during the past 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled for days one and two (20-21 May) due to weak effects from the CME observed at 18/1842Z off the west limb. A return to quiet conditions is expected on day three (22 May). III. Event Probabilities 20 May-22 May Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 19 May 084 Predicted 20 May-22 May 084/082/080 90 Day Mean 19 May 109 V. Geomagnetic A Indices Observed Afr/Ap 18 May 004/006 Estimated Afr/Ap 19 May 004/005 Predicted Afr/Ap 20 May-22 May 007/007-007/007-005/005 VI. Geomagnetic Activity Probabilities 20 May-22 May A. Middle Latitudes Active 15/15/05 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 25/25/05 Minor storm 05/05/01 Major-severe storm 01/01/01