:Product: 20000304RSGA.txt :Issued: 2000 Mar 04 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 064 ISSUED AT 2200Z ON 04 MAR 2000 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 03/2100Z TO 04/2100Z: SOLAR ACTIVITY HAS BEEN LOW FOR THE PAST 24 HOURS. REGION 8882 (S15W83) PRODUCED TODAY'S LARGEST EVENT, A C6/SF AT 03/2345Z. TWO NEW SUNSPOT GROUPS EMERGED: REGION 8899 (S11E19) AND REGION 8900 (S15E16). REGION 8900 SHOWED STEADY GROWTH AND PRODUCED OCCASIONAL SUBFLARES. THE GROUP DEVELOPED INTO A SMALL, D-TYPE REGION BY THE END OF THE REPORTING PERIOD. REGION 8891 (S15W29) IS STILL THE LARGEST GROUP ON THE DISK BUT SHOWED SIGNS OF DECAY AND WEAKENING MAGNETIC FIELDS. AN 11 DEGREE FILAMENT NEAR N40W36 DISAPPEARED BETWEEN 0804-0900Z. X-RAY IMAGES FROM THE YOHKOH SPACECRAFT SHOWED AN ENHANCED LOOP SYSTEM FORMED IN ASSOCIATION WITH THE DISAPPEARANCE, SUGGESTING THAT A CME OCCURRED. ANOTHER 15 DEGREE FILAMENT NEAR S35E50 DISAPPEARED AT ABOUT 1800Z. THIS DISAPPEARANCE WAS FOLLOWED BY PARALLEL H-ALPHA RIBBONS, A WEAK X-RAY ENHANCEMENT, A WEAK TYPE II SWEEP, AND A FAINT CME SIGNATURE AS OBSERVED BY THE MAUNA LOA CORONAGRAPH, ALL OF WHICH INDICATE ERUPTION OF THE FILAMENT. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. A GRADUAL DOWNWARD TREND IN ACTIVITY IS EXPECTED WITH THE DEPARTURE OF REGIONS 8886 AND 8882 OVER THE NEXT THREE DAYS. THERE REMAINS A SLIGHT CHANCE FOR A MAJOR FLARE EVENT. REGION 8891 CONTINUES TO BE THE MAIN THREAT FOR AN ISOLATED MAJOR EVENT. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 03/2100Z TO 04/2100Z: THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND OBSERVATIONS AT THE L1 POINT GAVE NO INDICATION OF RECENT FLARE-ASSOCIATED CORONAL MASS EJECTION ACTIVITY. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED TOMORROW, WITH A POSSIBILITY FOR SOME ACTIVE PERIODS. PREDOMINANTLY UNSETTLED LEVELS SHOULD FOLLOW ON THE SECOND DAY, AND CONDITIONS SHOULD BE QUIET TO UNSETTLED ON THE THIRD DAY. THERE IS A SLIGHT, BUT DECREASING POSSIBILITY THAT A GLANCING BLOW FROM CME ACTIVITY OF 2 MARCH WILL BE SEEN OVER THE NEXT 24 HOURS. III. EVENT PROBABILITIES 05 MAR-07 MAR CLASS M 45/45/40 CLASS X 15/10/05 PROTON 20/15/10 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 04 MAR 200 PREDICTED 05 MAR-07 MAR 195/190/190 90 DAY MEAN 04 MAR 170 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 03 MAR 005/005 ESTIMATED AFR/AP 04 MAR 005/005 PREDICTED AFR/AP 05 MAR-07 MAR 015/018-010/015-005/010 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 05 MAR-07 MAR A. MIDDLE LATITUDES ACTIVE 25/20/15 MINOR STORM 15/10/05 MAJOR-SEVERE STORM 05/05/05 B. HIGH LATITUDES ACTIVE 30/25/20 MINOR STORM 15/10/10 MAJOR-SEVERE STORM 05/05/05