:Product: 0525RSGA.txt :Issued: 2010 May 25 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 145 Issued at 2200Z on 25 May 2010 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was very low. Region 1072 (S15W36) produced an impulsive B6/Sf flare at 25/1551Z. IB. Solar Activity Forecast: Solar activity is expected to remain very low, with a slight chance of a C-class event from Region 1072. IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been quiet. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet on day one (26 May) and partway through day two (27 May). An increase to active levels is expected late on day two (27 May) and partway through day three (28 May) due to the arrival of the CME observed on 23 May. Predominately unsettled to active levels with a chance for isolated minor storm levels are expected later on day three (28 May) due to the arrival of the CME observed on 24 May. III. Event Probabilities 26 May-28 May Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 25 May 073 Predicted 26 May-28 May 075/076/078 90 Day Mean 25 May 078 V. Geomagnetic A Indices Observed Afr/Ap 24 May 000/002 Estimated Afr/Ap 25 May 004/005 Predicted Afr/Ap 26 May-28 May 005/002-010/015-020/020 VI. Geomagnetic Activity Probabilities 26 May-28 May A. Middle Latitudes Active 05/35/50 Minor storm 01/05/15 Major-severe storm 01/01/05 B. High Latitudes Active 05/40/50 Minor storm 01/15/25 Major-severe storm 01/10/15