:Product: 0920RSGA.txt :Issued: 2010 Sep 20 2201 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 263 Issued at 2200Z on 20 Sep 2010 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was low. A C2 X-ray event was observed at 20/1945Z. The event appeared to originate from an emerging flux region on the east limb near N20. Region 1106 (S21W53) decayed in the trailer portion of the spot group, but maintained a bi-polar magnetic configuration. Region 1108 (S30E24) exhibited little change during the period. IB. Solar Activity Forecast: Solar activity is expected to be very low to low with a slight chance of M-class activity for the next three days (21 - 23 September). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels, with isolated active periods, for day one (21 September). Mostly unsettled, with isolated active to minor storm levels, are expected on days two and three (22 - 23 September). The increase in activity is due to a large, recurrent coronal hole high speed stream. III. Event Probabilities 21 Sep-23 Sep Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 20 Sep 083 Predicted 21 Sep-23 Sep 083/083/084 90 Day Mean 20 Sep 078 V. Geomagnetic A Indices Observed Afr/Ap 19 Sep 002/004 Estimated Afr/Ap 20 Sep 003/005 Predicted Afr/Ap 21 Sep-23 Sep 008/012-015/018-015/018 VI. Geomagnetic Activity Probabilities 21 Sep-23 Sep A. Middle Latitudes Active 20/30/30 Minor storm 01/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 25/35/35 Minor storm 05/10/10 Major-severe storm 01/01/01