:Product: 0410RSGA.txt :Issued: 2011 Apr 10 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 100 Issued at 2200Z on 10 Apr 2011 IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity was very low. Only B-class events were observed. Region 1185 (N18E01) grew from an area of 30 millionths to 60 millionths. Region 1186 (N23E06) grew from 40 millionths to 70 millionths. Regions 1188 (S24W34) and 1189 (N23W16) are now plage regions. A CME was observed on SOHO/LASCO C2 imagery on the Northeast limb at approximately 10/0312Z. IB. Solar Activity Forecast: Solar activity is expected to be very low to low with a slight chance for C-class flares for the next three days (11 - 13 April). IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field was at quiet levels. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels, with isolated active levels at mid-latitudes on day one (11 April). The increase in activity is due to a coronal hole high-speed stream. Activity is expected to decrease to mostly quiet levels on days two and three (12 - 13 April) as the coronal hole high-speed stream effects wane. The CME referenced in paragraph 1A, is not expected to be geoeffective. III. Event Probabilities 11 Apr-13 Apr Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 10 Apr 105 Predicted 11 Apr-13 Apr 095/100/100 90 Day Mean 10 Apr 101 V. Geomagnetic A Indices Observed Afr/Ap 09 Apr 004/010 Estimated Afr/Ap 10 Apr 005/005 Predicted Afr/Ap 11 Apr-13 Apr 010/012-005/005-005/005 VI. Geomagnetic Activity Probabilities 11 Apr-13 Apr A. Middle Latitudes Active 35/20/10 Minor storm 05/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 40/25/15 Minor storm 10/01/01 Major-severe storm 05/01/01