:Product: 20020911RSGA.txt :Issued: 2002 Sep 11 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 254 Issued at 2200Z on 11 Sep 2002 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been moderate. Region 105 (S09E28) produced the largest event of the period, an M2/2b flare at 11/0735 UTC with an associated tenflare (230 sfu). Region 107 (N11E30) was a source of several C-class flares during the period, and Region 100 (S19W64) also produced a C-class flare. Region 103 (N14W33) has remained quiescent, but appears somewhat more compact today and retains moderate magnetic complexity. IB. Solar Activity Forecast: Solar activity is expected to be at moderate levels for the next three days. Region 105 is a likely source of further M-class activity. Regions 103 and 107 may become more active during the period and could produce M-class flares as well. IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: Geomagnetic field conditions have ranged from quiet to major storm levels. Onset of coronal hole high speed stream effects have been evident since about 11/0900 UTC, and the single period of major storm conditions observed at higher latitudes occurred shortly thereafter. The remainder of the day had conditions in the unsettled to minor storm range. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mainly unsettled to active for the next 24-48 hours. Isolated minor storm conditions may also occur, especially at higher latitudes. Conditions are expected to be in the quiet to unsettled range by the end of the forecast period. III. Event Probabilities 12 Sep-14 Sep Class M 65/65/65 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 11 Sep 216 Predicted 12 Sep-14 Sep 220/220/225 90 Day Mean 11 Sep 173 V. Geomagnetic A Indices Observed Afr/Ap 10 Sep 014/024 Estimated Afr/Ap 11 Sep 020/025 Predicted Afr/Ap 12 Sep-14 Sep 018/018-015/018-012/015 VI. Geomagnetic Activity Probabilities 12 Sep-14 Sep A. Middle Latitudes Active 35/30/25 Minor storm 10/10/05 Major-severe storm 05/01/01 B. High Latitudes Active 35/35/30 Minor storm 15/15/10 Major-severe storm 05/05/01