:Product: 20020920RSGA.txt :Issued: 2002 Sep 20 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Environment 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 2002 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was moderate. New Region 126 (S24E62) produced two M-class flares this period. Both were M1/Sf flares, at 20/0512Z and 0928Z, and both were accompanied by minor centimetric bursts. Limb proximity makes it too difficult to accurately assess Region 126's complexity, but initial measurements indicate a D type group with 200 millionths of white light areal coverage. Region 119 (S14W24) continues to grow and the delta configuration is now more pronounced. Despite this region's moderate complexity, flare output has been nothing more than occasional minor C-class flares. Early in the period, a large CME was observed, originating along a filament channel near S30E12. The ejecta does not appear earthward directed. New Regions 127 (S14E19) and 128 (N11E63) were numbered today. Region 127 is in close proximity to Region 122 (S18E21), but the consensus is that these are separate regions. IB. Solar Activity Forecast: Solar activity is expected to continue at low to moderate levels. Low M-class flares are possible from Regions 119 and 126. IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet to unsettled. Solar wind speed began the period near 700 km/s following the arrival of a CME earlier yesterday. However, a weak IMF with sustained northward Bz offset any significant impact on the geomagnetic field. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain at quiet to unsettled levels for the next three days. III. Event Probabilities 21 Sep-23 Sep Class M 50/50/50 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Sep 164 Predicted 21 Sep-23 Sep 165/160/160 90 Day Mean 20 Sep 178 V. Geomagnetic A Indices Observed Afr/Ap 19 Sep 011/013 Estimated Afr/Ap 20 Sep 006/010 Predicted Afr/Ap 21 Sep-23 Sep 008/012-008/010-008/010 VI. Geomagnetic Activity Probabilities 21 Sep-23 Sep A. Middle Latitudes Active 20/15/15 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 25/20/20 Minor storm 05/05/05 Major-severe storm 01/01/01