:Product: 20020912RSGA.txt :Issued: 2002 Sep 12 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 255 Issued at 2200Z on 12 Sep 2002 IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity fell to low levels. The largest event of the period was a C4/Sf flare at 12/0018 UTC from Region 107 (N11E16). Region 105 (S08E16) produced several lesser C-class flares, including an apparent one in progress at the end of the period. This region remains the largest on the visible disk. It's easternmost spots still retain a beta-gamma-delta magnetic configuration, while the western spot group appears to have lost some complexity. Region 107 continues in a pattern of slow growth and frequent flare production. Three new regions were numbered today, all relatively small and simply structured at present. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate for the next three days. M-class activity appears possible from Regions 105 and 107. IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field was mainly unsettled to active. One isolated quiet period was observed at mid-latitudes. Coronal hole high speed stream effects continued to be the main source of activity. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to active during the first day of the forecast period, with a gradual reduction towards quiet to unsettled conditions thereafter. Greater than 2 MeV electron flux at geosynchronous orbit may reach high levels during the period. III. Event Probabilities 13 Sep-15 Sep Class M 50/50/50 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 12 Sep 212 Predicted 13 Sep-15 Sep 215/220/225 90 Day Mean 12 Sep 174 V. Geomagnetic A Indices Observed Afr/Ap 11 Sep 016/028 Estimated Afr/Ap 12 Sep 013/015 Predicted Afr/Ap 13 Sep-15 Sep 012/012-012/012-008/012 VI. Geomagnetic Activity Probabilities 13 Sep-15 Sep A. Middle Latitudes Active 25/25/20 Minor storm 05/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 30/30/25 Minor storm 05/05/05 Major-severe storm 01/01/01