:Product: 0921RSGA.txt :Issued: 2012 Sep 21 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 265 Issued at 2200Z on 21 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was very low. The largest x-ray event was a B8/Sf at 21/1221Z produced by Region 1573 (N18W04). The largest spot group on the solar disk, Region 1575 (N08E37), remains near 250 millionths in area with a Beta magnetic configuration. Two asymmetrical partial halo CMEs were observed in SOHO LASCO during the period. Both events were determined to be backside sourced, and are not expected to impact Earth. IB. Solar Activity Forecast: Solar activity is expected to be very low to low for the next 3 days (22-24 September). IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet during the period, despite the influence of a weak coronal hole (CH) high speed stream. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled for day 1 (22 September) as CH effects wane. Conditions are expected to be mostly quiet for days 2-3 (23-24 September). III. Event Probabilities 22 Sep-24 Sep Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Sep 117 Predicted 22 Sep-24 Sep 118/120/120 90 Day Mean 21 Sep 122 V. Geomagnetic A Indices Observed Afr/Ap 20 Sep 010/010 Estimated Afr/Ap 21 Sep 005/006 Predicted Afr/Ap 22 Sep-24 Sep 008/008-006/005-006/005 VI. Geomagnetic Activity Probabilities 22 Sep-24 Sep A. Middle Latitudes Active 10/01/01 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor storm 20/10/10 Major-severe storm 15/05/05