:Product: 20021224RSGA.txt :Issued: 2002 Dec 24 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 358 Issued at 2200Z on 24 Dec 2002 IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: Solar activity was at low levels. Region 224 (S14W81) produced two C5 flares. The first one at 24/0527 UTC and the second one at 24/1451 UTC. Region 224 has stopped its growth phase of the last few days. Region 226 (S28W89) continues to gradually decay and has simplied to a beta magnetic configuration. New Region 234 (N18E73) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. Region 230 has the potential for M-class activity. Regions 224 and 226 also have M-class potential as they rotate beyond the west limb. IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field was at quiet to active levels. A weak transient was observed by the NASA/ACE spacecraft at approximately 24/1300 UTC. Solar wind speed increased to near 575 km/s and Bz was slightly negative. The greater than 2 MeV electron flux at geo-synchronous orbit reached high levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled with a chance of isolated active conditions. Isolated active conditions may continue into day one of the forecast period. By late on day one and through day two activity is expected to be quiet to unsettled. Coronal hole effects are expected to commence on day three of the period with isolated active conditions possible. III. Event Probabilities 25 Dec-27 Dec Class M 40/30/25 Class X 05/05/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 24 Dec 147 Predicted 25 Dec-27 Dec 145/140/140 90 Day Mean 24 Dec 167 V. Geomagnetic A Indices Observed Afr/Ap 23 Dec 012/026 Estimated Afr/Ap 24 Dec 015/015 Predicted Afr/Ap 25 Dec-27 Dec 012/010-008/012-012/015 VI. Geomagnetic Activity Probabilities 25 Dec-27 Dec A. Middle Latitudes Active 15/10/20 Minor storm 05/01/10 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/25 Minor storm 05/05/15 Major-severe storm 01/01/01