:Product: 20031225RSGA.txt :Issued: 2003 Dec 25 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 359 Issued at 2200Z on 25 Dec 2003 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was at low levels. Region 528 (N10W18) produced the largest flare of the period, a long duration C5/Sf flare at 25/0825Z. This region has shown a slight growth over the period and retains a beta-gamma magnetic structure. Region 525 (N09W49) produced several low level C-class flares early in the period. No spots were visible in this region at the time of this writing. New Region 532 (S11E02) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at low levels. Region 528 has a slight chance of producing a low level M-class flare. IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field was at quiet to unsettled levels. The solar wind speed continues a gradual decline, ending the period below 380 km/s. The greater than 2 MeV electron fluxes at geosynchronous orbit reached high levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominantly quiet levels with isolated unsettled conditions possible throughout the period. III. Event Probabilities 26 Dec-28 Dec Class M 15/15/15 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 25 Dec 139 Predicted 26 Dec-28 Dec 140/135/135 90 Day Mean 25 Dec 136 V. Geomagnetic A Indices Observed Afr/Ap 24 Dec 006/008 Estimated Afr/Ap 25 Dec 006/010 Predicted Afr/Ap 26 Dec-28 Dec 006/010-008/010-010/010 VI. Geomagnetic Activity Probabilities 26 Dec-28 Dec A. Middle Latitudes Active 10/10/15 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor storm 05/05/05 Major-severe storm 01/01/01