000 WTNT42 KNHC 092033 TCDAT2 TROPICAL STORM LESLIE DISCUSSION NUMBER 42 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122012 500 PM AST SUN SEP 09 2012 ALTHOUGH DVORAK CLASSIFICATIONS FROM TAFB AND SAB WERE T3.5 AT 18Z...SINCE THEN THE COLD CLOUD TOPS HAVE WARMED A BIT AND THE BANDING HAS BECOME LESS SOLID. THE ADVISORY INTENSITY WILL REMAIN 50 KT. LESLIE CONTINUES TO LACK A WELL-DEFINED INNER CORE...WHICH SHOULD MITIGATE AGAINST OTHERWISE FAVORABLE ENVIRONMENTAL CONDITIONS FOR THE NEXT 36 HOURS OR SO. BOTH THE TROPICAL AND GLOBAL GUIDANCE INDICATE THAT LESLIE WILL BE AT OR AT LEAST NEAR HURRICANE STRENGTH ON ITS APPROACH TO NEWFOUNDLAND. AFTER 36 HOURS...SSTS COOL AND SOUTHWESTERLY SHEAR INCREASES MARKEDLY...BUT THE GLOBAL GUIDANCE SUGGESTS THAT LESLIE WILL CONTINUE TO BE A VIGOROUS EXTRATROPICAL CYCLONE FOR AT LEAST THE NEXT THREE DAYS. BASED ON THE GFS AND ECMWF FIELDS...LESLIE WILL BE MERGING WITH A FRONTAL SYSTEM ABOUT THE TIME IT REACHES NEWFOUNDLAND. THE INITIAL MOTION IS 010/12. THERE HAS BEEN NO CHANGE TO THE TRACK FORECAST PHILOSOPHY WITH THIS ADVISORY...ALTHOUGH THE CURRENT FORECAST IS A LITTLE FASTER THAN THE PREVIOUS ONE. AS A MID-TROPOSPHERIC TROUGH MOVES OFF THE NORTHEAST U.S. COAST...THE CYCLONE IS EXPECTED TO ACCELERATE NORTH-NORTHEASTWARD IN THE FLOW ON THE EAST SIDE OF THE TROUGH OVER THE NEXT COUPLE OF DAYS. IN 3-4 DAYS...THE POST-TROPICAL CYCLONE SHOULD TURN EAST-NORTHEASTWARD IN THE HIGHER LATITUDE WESTERLIES. LONG-PERIOD SWELLS FROM LESLIE ARE EXPECTED TO PRODUCE ROUGH SURF AND LIFE-THREATENING RIP CURRENTS ON BERMUDA AND ALONG MUCH OF THE U.S. EAST COAST FOR THE NEXT COUPLE OF DAYS. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 33.4N 62.1W 50 KT 60 MPH 12H 10/0600Z 35.1N 61.6W 55 KT 65 MPH 24H 10/1800Z 38.5N 60.0W 60 KT 70 MPH 36H 11/0600Z 44.1N 56.7W 65 KT 75 MPH 48H 11/1800Z 51.0N 51.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 12/1800Z 60.0N 32.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 13/1800Z 63.5N 9.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 14/1800Z...ABSORBED $$ FORECASTER FRANKLIN