:Product: 19991111RSGA.txt :Issued: 1999 Nov 11 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 315 ISSUED AT 2200Z ON 11 NOV 1999 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 10/2100Z TO 11/2100Z: SOLAR ACTIVITY REMAINED MODERATE. EARLY IN THE PERIOD, REGION 8753 (N18W36) PRODUCED AN M1/1N FLARE AT 10/2213Z. MODERATE CENTIMETRIC RADIO BURSTS ACCOMPANIED THIS EVENT. DECAY OCCURRED IN THIS REGION IN THE PAST 24 HOURS. REGION 8759 (N10E20) GENERATED A C8/1N AT 11/1449Z. THIS REGION ALSO DECAYED IN WHITE LIGHT AREA DURING THE PERIOD. REGION 8760 (N13W17) PRODUCED SEVERAL SUBFLARES AND CONTINUED TO EMERGE BUT AT A SLOW RATE. A MODERATE SIZE NEW REGION, 8765 (S10E73), ROTATED OVER THE LIMB BEHIND REGION 8763 (S14E60). REGION 8763 PRODUCED SEVERAL LOW LEVEL C-CLASS FLARES. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY SHOULD REMAIN GENERALLY MODERATE. REGIONS 8759 AND 8760 REMAIN AS THE LIKELY SOURCES OF M-CLASS FLARES DUE TO THEIR SIZE AND SLIGHTLY MIXED MAGNETIC FIELDS. HOWEVER, SEVERAL OTHER LESSER REGIONS COULD PRODUCE ISOLATED M-CLASS EVENTS. THERE REMAINS A SLIGHT POSSIBILITY OF A MAJOR FLARE FROM REGIONS 8759 AND 8760. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 10/2100Z TO 11/2100Z: THE GEOMAGNETIC FIELD WAS AT QUIET TO MINOR STORM LEVELS. THE MOST DISTURBED PERIOD WAS FROM 11/0300-1200Z. SOLAR WIND VELOCITY INCREASED TO AROUND 650 KM/S AND DENSITY REMAINED LOW INDICATING THE EARTH REMAINS IN THE CORONAL HOLE STREAM MENTIONED OVER THE LAST FEW DAYS. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT REACHED HIGH LEVELS DURING THE PERIOD. NO SOHO CORONAGRAPH DATA HAVE BEEN AVAILABLE SINCE 08 NOV. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD SHOULD REMAIN DISTURBED ON 12 NOV. ACTIVE TO MINOR STORM LEVELS ARE EXPECTED ON THAT DAY. ON 13 NOV, THE FIELD SHOULD BECOME UNSETTLED TO SLIGHTLY ACTIVE AS THE CURRENT CORONAL HOLE RELATED DISTURBANCE SUBSIDES. MOSTLY QUIET CONDITIONS ARE FORECAST FOR 14 NOV. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS SHOULD REMAIN ELEVATED FOR THE NEXT THREE DAYS. III. EVENT PROBABILITIES 12 NOV-14 NOV CLASS M 70/70/70 CLASS X 15/15/15 PROTON 10/10/10 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 11 NOV 240 PREDICTED 12 NOV-14 NOV 242/245/245 90 DAY MEAN 11 NOV 159 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 10 NOV 013/012 ESTIMATED AFR/AP 11 NOV 023/025 PREDICTED AFR/AP 12 NOV-14 NOV 018/018-010/010-008/008 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 12 NOV-14 NOV A. MIDDLE LATITUDES ACTIVE 40/30/10 MINOR STORM 25/15/05 MAJOR-SEVERE STORM 05/01/01 B. HIGH LATITUDES ACTIVE 40/30/15 MINOR STORM 30/15/05 MAJOR-SEVERE STORM 10/01/01