000WTNT42 KNHC 110258TCDAT2TROPICAL STORM LESLIE DISCUSSION NUMBER 47NWS NATIONAL HURRICANE CENTER MIAMI FL AL1220121100 PM AST MON SEP 10 2012THE OVERALL CLOUD PATTERN HAS NOT CHANGED MUCH SINCE THE PREVIOUSADVISORY OTHER THAN CLOUD TOPS HAVE COOLED SLIGHTLY TO THE NORTHAND EAST OF THE CENTER. AN EARLIER ASCAT OVERPASS INDICATED THATLESLIE HAS WINDS OF AT LEAST 60 KT TO THE NORTH AND NORTHEAST OFTHE CENTER. HOWEVER...RECENT DATA FROM CANADIAN BUOY 44139 LOCATEDABOUT 100 NMI NORTH-NORTHEAST OF THE CENTER SUGGEST THAT THEMAXIMUM WINDS ASSOCIATED WITH LESLIE HAVE LIKELY SHIFTED TO THEEAST AND SOUTHEAST OF THE CENTER SINCE THE WINDS AT THAT BUOY HAVENOT INCREASED TO MORE THAN 25 KT. THE ASYMMETRY OF THE WINDFIELDAND THE CONVECTIVE PATTERN IS MORE INDICATIVE OF AN EXTRATROPICALRATHER THAN A TROPICAL CYCLONE DUE TO A STRONG COLD FRONTAL SYSTEMNOW LOCATED ONLY ABOUT 100 NMI WEST OF THE CENTER. IT IS QUITEPOSSIBLE THAT THE FRONTAL SYSTEM WILL CATCH UP TO AND MERGE WITHTHE CIRCULATION CENTER BEFORE LESLIE REACHES NEWFOUNDLAND.REGARDLESS OF THE STATUS OF THE CYCLONE AT LANDFALL TUESDAYMORNING...IT WILL STILL BE A POWERFUL LOW PRESSURE SYSTEM.ONCE LESLIE BECOMES POST-TROPICAL...IT WILL REMAIN A VERY STRONGEXTRATROPICAL CYCLONE FOR THE NEXT FEW DAYS OVER THE COLD WATERS OFTHE FAR NORTH ATLANTIC.LESLIE HAS CONTINUED TO ACCELERATE AND IS NOW MOVING TOWARD THENORTH-NORTHEAST AT ABOUT 35 KT. THE CYCLONE IS EMBEDDED IN STRONGSOUTH-SOUTHWESTERLY DEEP-LAYER FLOW AHEAD OF A VIGOROUS NEGATIVELYTILTED MID-LATITUDE TROUGH THAT IS ORIENTED NORTHWEST-TO-SOUTHEASTACROSS MAINE AND THE CANADIAN MARITIMES. AN ADDITIONAL INCREASEIN FORWARD SPEED IS ANTICIPATED AS THE TROUGH LIFTS OUT TO THENORTHEAST...AND THE CENTER OF LESLIE IS FORECAST TO MAKE LANDFALLOVER SOUTHEASTERN NEWFOUNDLAND IN ABOUT 12 HOURS OR SO. THE OFFICIALFORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY...AND LIES CLOSETO THE DYNAMICAL CONSENSUS MODELS TVCN AND TV15.LONG-PERIOD SWELLS FROM LESLIE ARE STILL EXPECTED TO PRODUCE ROUGHSURF AND LIFE-THREATENING RIP CURRENTS ON BERMUDA AND ALONG MUCH OFTHE U.S. EAST COAST...AND THE CANADIAN ATLANTIC PROVINCES.FORECAST POSITIONS AND MAX WINDSINIT 11/0300Z 42.7N 57.5W 60 KT 70 MPH 12H 11/1200Z 47.6N 54.1W 60 KT 70 MPH...INLAND 24H 12/0000Z 54.2N 47.2W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 12/1200Z 59.8N 38.6W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 13/0000Z 62.5N 29.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 14/0000Z 62.5N 10.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 15/0000Z...ABSORBED BY LARGER EXTRATROPICAL LOW$$FORECASTER STEWART