:Product: 20010831RSGA.txt :Issued: 2001 Aug 31 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 243 Issued at 2200Z on 31 Aug 2001 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity was moderate due to a single M-class event during the period. Region 9601 (N14E32) produced an M1/Sn event with an accompanying 270 sfu Tenflare and a Type II radio sweep (velocity est. 961 km/s). LASCO imagery does not show any signs of an earth-directed coronal mass ejection from this event. Region 9601 has continued to show growth over the period and is capable of producing a major flare at any time. Region 9591 (S20W39) has shown some signs of minor decay during the period. It continues to retain a beta-gamma-delta magnetic configuration and is still capable of producing an isolated major flare before it rotates over the western limb on September 04-05. There are only three other spotted regions on the disk at this time. None of which have produced any significant activity. IB. Solar Activity Forecast: Solar activity is expected to be moderate to high. Region 9591 and 9601 are expected to continue to produce isolated M-class events and both are capable of producing a major flare during the forecast period. IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field was mostly quiet to unsettled with isolated active periods. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to active with recurrent coronal hole effects beginning on 01 September. Barring any earth-directed coronal mass ejections, conditions should return to mostly quiet to unsettled on 03 September. III. Event Probabilities 01 Sep-03 Sep Class M 80/80/80 Class X 25/25/25 Proton 25/25/25 PCAF yellow IV. Penticton 10.7 cm Flux Observed 31 Aug 189 Predicted 01 Sep-03 Sep 190/190/190 90 Day Mean 31 Aug 156 V. Geomagnetic A Indices Observed Afr/Ap 30 Aug 008/013 Estimated Afr/Ap 31 Aug 015/015 Predicted Afr/Ap 01 Sep-03 Sep 015/015-015/025-012/020 VI. Geomagnetic Activity Probabilities 01 Sep-03 Sep A. Middle Latitudes Active 25/25/20 Minor storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 30/30/25 Minor storm 15/15/10 Major-severe storm 01/01/01