:Product: 0412RSGA.txt :Issued: 2011 Apr 12 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 102 Issued at 2200Z on 12 Apr 2011 IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity was low. Region 1190 (N15E12) produced three C-class flares during the period. The largest was a C3 event at 12/0607Z. Region 1190 increased in area from 40 millionths to approximately 70 millionths. New Regions 1191 (N09E73) and 1192 (N10E03) were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be low. C-class flares are likely for the next three days (13 - 15 April). IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field was at quiet to minor storm levels. Two periods of K=5 were observed at high latitudes during the period. The increase was in response to a coronal hole high-speed stream. Solar wind speeds measured at the ACE Spacecraft increased from approximately 550 km/s to approximately 650 km/s during the past 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at mostly quiet levels for the next three days (13 - 15 April) as the coronal hole high-speed stream effects decrease. III. Event Probabilities 13 Apr-15 Apr Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 12 Apr 110 Predicted 13 Apr-15 Apr 110/110/110 90 Day Mean 12 Apr 101 V. Geomagnetic A Indices Observed Afr/Ap 11 Apr 005/009 Estimated Afr/Ap 12 Apr 015/015 Predicted Afr/Ap 13 Apr-15 Apr 005/005-005/005-005/005 VI. Geomagnetic Activity Probabilities 13 Apr-15 Apr A. Middle Latitudes Active 20/10/10 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 25/15/15 Minor storm 01/01/01 Major-severe storm 01/01/01