:Product: 20011211RSGA.txt :Issued: 2001 Dec 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 345 Issued at 2200Z on 11 Dec 2001 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity increased to high levels. Region 9733 (N15E32) produced an impulsive X2/Sf flare at 11/0808 UTC. The flare was associated with Type II and IV radio sweeps, a 2600 sfu Tenflare, and a coronal mass ejection (CME) that did not appear to be Earth-directed. Region 9733 showed increased area and magnetic complexity with at least one magnetic delta configuration within its northern-most trailer spots. Region 9727 (S22W36) produced an impulsive M1/2n flare at 11/1451 UTC associated with relatively minor radio emission. This region showed minor growth in spot number and area with two delta magnetic configurations evident within its large trailing spot mass. IB. Solar Activity Forecast: Solar activity is expected to be at moderate to high levels. Isolated M-class flares are expected from Regions 9727 and 9733. Either region could produce a major flare during the period as well. IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: Geomagnetic field activity was at quiet levels. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at quiet to unsettled levels through the period. There will be a chance for a proton flare from Regions 9727 and 9733. III. Event Probabilities 12 Dec-14 Dec Class M 80/80/80 Class X 20/20/20 Proton 20/20/20 PCAF Yellow IV. Penticton 10.7 cm Flux Observed 11 Dec 221 Predicted 12 Dec-14 Dec 215/210/210 90 Day Mean 11 Dec 218 V. Geomagnetic A Indices Observed Afr/Ap 10 Dec 003/004 Estimated Afr/Ap 11 Dec 005/005 Predicted Afr/Ap 12 Dec-14 Dec 007/008-012/010-012/015 VI. Geomagnetic Activity Probabilities 12 Dec-14 Dec A. Middle Latitudes Active 15/20/20 Minor storm 05/10/10 Major-severe storm 01/01/01 B. High Latitudes Active 20/25/25 Minor storm 05/15/15 Major-severe storm 01/01/01