:Product: 19971226RSGA.txt :Issued: 1997 Dec 26 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 360 ISSUED AT 2200Z ON 26 DEC 1997 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 25/2100Z TO 26/2100Z: SOLAR ACTIVITY WAS LOW. REGION 8124 (S22E01) PRODUCED A SINGLE C2/SF FLARE AT 26/0557Z. SPACE-BASED SENSORS OBSERVED A THREE-QUARTER HALO CORONAL MASS EJECTION COINCIDENT WITH THE FLARE. FURTHER DATA IS STILL SKETCHY, BUT NO RADIO EMMISSION WAS DETECTED WITH THE EVENT. REGION 8124 CONTINUES TO DECAY SLOWLY. REGION 8126 (N20E41) HAS GROWN SLIGHTLY BUT HAS REMAINED QUIET AND STABLE. NEW REGION 8127 (S17W54), A SMALL AXX SPOT GROUP, WAS NUMBERED TODAY. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. REGION 8124 STILL HAS A GOOD CHANCE OF PRODUCING C-CLASS ACTIVITY AND A SMALL CHANCE OF ISOLATED M-CLASS FLARING. REGION 8126 HAS A CHANCE OF ISOLATED C-CLASS ACTIVITY. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 25/2100Z TO 26/2100Z: THE GEOMAGNETIC FIELD WAS QUIET AT ALL LATITUDES. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN QUIET FOR THE ENTIRE FORECAST PERIOD. THE POSSIBILITY OF INCREASED ACTIVITY BY DAY FOUR, RESULTING FROM TODAY'S CME, IS STILL BEING EVALUATED. III. EVENT PROBABILITIES 27 DEC-29 DEC CLASS M 05/05/05 CLASS X 01/01/01 PROTON 01/01/01 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 26 DEC 105 PREDICTED 27 DEC-29 DEC 104/104/102 90 DAY MEAN 26 DEC 094 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 25 DEC 002/002 ESTIMATED AFR/AP 26 DEC 002/002 PREDICTED AFR/AP 27 DEC-29 DEC 005/005-005/005-005/005 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 27 DEC-29 DEC A. MIDDLE LATITUDES ACTIVE 10/10/10 MINOR STORM 05/05/05 MAJOR-SEVERE STORM 01/01/01 B. HIGH LATITUDES ACTIVE 10/10/10 MINOR STORM 05/05/05 MAJOR-SEVERE STORM 01/01/01