:Product: 20021218RSGA.txt :Issued: 2002 Dec 18 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 352 Issued at 2200Z on 18 Dec 2002 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was at moderate levels. Region 226 (S28W15) produced two M-class flares today. The largest was an M2.4/1n flare that occurred at 18/0642 UTC, a slightly smaller M1.6/Sf flare occurred at 17/2335 UTC, with several lesser C-class flares originating from this region today as well. The magnetic delta spot configuration remains evident in the intermediate cluster of spots. Region 229 (N19E12) did not produce optically correlated flare activity during the period although the areal spot coverage has increased and the magnetic gamma characteristics remain intact. No new regions were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at moderate levels. Regions 226 and 229 have the potential of producing M-class event activity. IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field was at quiet to unsettled levels. The greater than 2 MeV electron flux at geosynchronous orbit reached moderate levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to minor storm levels once the onset of the recurrent coronal hole high speed stream begins, which is expected to occur on day one of the forecast period. Day two should see predominantly unsettled to active conditions with isolated periods of minor storm levels. A return to predominantly unsettled conditions with isolated active periods should occur on day three. III. Event Probabilities 19 Dec-21 Dec Class M 60/60/60 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Dec 197 Predicted 19 Dec-21 Dec 195/195/195 90 Day Mean 18 Dec 165 V. Geomagnetic A Indices Observed Afr/Ap 17 Dec 002/006 Estimated Afr/Ap 18 Dec 008/012 Predicted Afr/Ap 19 Dec-21 Dec 020/035-018/020-010/012 VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec A. Middle Latitudes Active 40/30/20 Minor storm 20/15/05 Major-severe storm 10/05/01 B. High Latitudes Active 45/35/25 Minor storm 35/25/10 Major-severe storm 15/10/05