:Product: 20021227RSGA.txt :Issued: 2002 Dec 27 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 361 Issued at 2200Z on 27 Dec 2002 IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity reached very low levels this period. Occasional subflares were observed in decaying Region 230 (S04W77) as it approached the west limb. New Region 236 emerged today and produced occasional plage enhancements and a B-class subflare late in the period The remaining regions are small with simple magnetic structure. IB. Solar Activity Forecast: Solar activity is expected to be very low to low for the next three days. IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field was at unsettled to minor storm levels with isolated major storm periods at higher latitudes. These storm conditions are a result of a large coronal hole that rotated into a geoeffective position late yesterday. Solar wind speed ranged from 700 - 800 km/s during the latter half of this period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to continue at unsettled to minor storm levels in response to the existing high speed, coronal hole stream. Expect the storming to gradually subside over days two and three of the period. III. Event Probabilities 28 Dec-30 Dec Class M 15/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 27 Dec 117 Predicted 28 Dec-30 Dec 115/115/115 90 Day Mean 27 Dec 166 V. Geomagnetic A Indices Observed Afr/Ap 26 Dec 008/015 Estimated Afr/Ap 27 Dec 025/040 Predicted Afr/Ap 28 Dec-30 Dec 020/025-015/030-008/020 VI. Geomagnetic Activity Probabilities 28 Dec-30 Dec A. Middle Latitudes Active 60/50/30 Minor storm 25/20/10 Major-severe storm 15/05/01 B. High Latitudes Active 40/40/40 Minor storm 40/40/20 Major-severe storm 20/20/05