000 WTNT41 KNHC 310249 TCDAT1 TROPICAL STORM DANIELLE DISCUSSION NUMBER 39 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010 1100 PM AST MON AUG 30 2010 SATELLITE IMAGES INDICATE THAT CONVECTION ASSOCIATED WITH DANIELLE HAS DECREASED SIGNIFICANTLY DURING THE PAST SEVERAL HOURS. IN ADDITION...AMSU MEASUREMENTS SHOW THAT THE WARM-CORE ASSOCIATED WITH THE CYCLONE HAS WEAKENED CONSIDERABLY DURING THE LAST 12 HOURS. THE INITIAL INTENSITY ESTIMATE IS MAINTAINED AT 60 KT BUT IS FAIRLY UNCERTAIN DUE TO THE LACK OF AVAILABLE OBSERVATIONAL DATA IN THE VICINITY OF DANIELLE IN RECENT HOURS. DUE TO THE ABSENCE OF CONVECTION...WEAKENING OF THE WARM-CORE AND A NON-TROPICAL SATELLITE APPEARANCE...DANIELLE IS BEING DECLARED A POST-TROPICAL STORM ON THIS ADVISORY. FULL EXTRATROPICAL TRANSITION IS EXPECTED TO BE A BIT MORE GRADUAL THAN INDICATED PREVIOUSLY...WITH BAROCLINIC ZONE TO THE NORTH OVERTAKING DANIELLE BY LATE TOMORROW. THE CENTER IS BECOMING MORE DIFFICULT TO DISTINGUISH...MAKING THE INITIAL MOTION ESTIMATE OF 070/13 SOMEWHAT UNCERTAIN. GLOBAL MODELS SHOW DANIELLE ROTATING CYCLONICALLY AND ACCELERATING AROUND A LARGE 500 MB CLOSED CYCLONE MOVING EASTWARD SOUTH OF GREENLAND DURING THE NEXT 24 TO 48 HOURS. THEREAFTER...DANIELLE IS EXPECTED TO BE ABSORBED WITHIN THE LARGE CYCLONIC GYRE ASSOCIATED WITH THIS FEATURE. THE OFFICIAL NHC FORECAST TRACK IS SIMILAR TO THE PREVIOUS ONE AND LIES CLOSE TO THE MULTI-MODEL CONSENSUS. FUTURE INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC. FORECAST POSITIONS AND MAX WINDS INITIAL 31/0300Z 41.3N 47.1W 60 KT...POST-TROPICAL 12HR VT 31/1200Z 42.3N 41.8W 55 KT...POST-TROP/EXTRATROP 24HR VT 01/0000Z 44.3N 34.0W 55 KT...POST-TROP/EXTRATROP 36HR VT 01/1200Z 47.0N 26.6W 50 KT...POST-TROP/EXTRATROP 48HR VT 02/0000Z 50.7N 22.8W 45 KT...POST-TROP/EXTRATROP 72HR VT 03/0000Z...ABSORBED $$ FORECASTER KIMBERLAIN