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#544100 (Received by flhurricane at: 4:35 AM 19.Sep.2012) TCDAT4 TROPICAL STORM NADINE DISCUSSION NUMBER 32 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142012 500 AM AST WED SEP 19 2012 NADINE DOES NOT LOOK LIKE A TYPICAL TROPICAL CYCLONE ON SATELLITE. THE CENTER IS DEVOID OF DEEP CONVECTION...AND MOST OF THE ASSOCIATED WEATHER IS WITHIN A CURVED BAND WELL TO THE NORTH OF THE CENTER. DVORAK ESTIMATES STILL SUPPORT AN INITIAL INTENSITY OF 45 KNOTS. IF THE DIAGNOSIS OF NADINE IS DIFFICULT...THE FORECAST IS EVEN MORE SO AND HIGHLY UNCERTAIN. THE CYCLONE IS MOVING WITHIN A STRONGLY SHEARED ENVIRONMENT AND OVER COOL WATERS. THIS NORMALLY WOULD LEAD TO WEAKENING. HOWEVER...MOST OF THE GLOBAL AND STATISTICAL MODELS KEEP NADINE AS A STRONG CYCLONE...AND EVEN STRENGTHEN IT A LITTLE BIT. I AM ASSUMING THAT THIS IS DUE TO THE FORECAST INTERACTION WITH A DEVELOPING BAROCLINIC ZONE...WHICH IN FACT...THE GFS ASSUMES WILL BECOME THE DOMINANT SYSTEM. ON THE CONTRARY...THE ECMWF MAKES NADINE THE PREVAILING ONE. REGARDLESS...IT APPEARS THAT THERE WILL BE A STRONG TROPICAL STORM...POST-TROPICAL CYCLONE...OR EXTRATROPICAL LOW DRIFTING EASTWARD TO THE SOUTH OF THE AZORES FOR A FEW DAYS. AT THIS TIME...THE NHC FORECAST FOLLOWS SOME CONTINUITY AND ASSUMES THAT THE TROPICAL CYCLONE WILL LOSE ALL ITS ASSOCIATED CONVECTION OVER THE COOLER WATERS AND BECOME A POST-TROPICAL CYCLONE IN 48 HOURS OR SO. THE TRACK GUIDANCE IS NOT IN GOOD AGREEMENT...BUT IS GRADUALLY TRENDING TOWARD THE GFS SOLUTION WHICH SHOWS A SLOW EASTWARD-MOVING OR MEANDERING CYCLONE TO THE SOUTH OR EAST OF THE AZORES. FORECAST POSITIONS AND MAX WINDS INIT 19/0900Z 36.4N 32.1W 45 KT 50 MPH 12H 19/1800Z 37.0N 32.0W 45 KT 50 MPH 24H 20/0600Z 36.6N 31.1W 45 KT 50 MPH 36H 20/1800Z 35.5N 29.8W 45 KT 50 MPH 48H 21/0600Z 34.5N 28.0W 45 KT 50 MPH...POST-TROPICAL 72H 22/0600Z 34.0N 25.0W 45 KT 50 MPH...POST-TROPICAL 96H 23/0600Z 34.0N 24.0W 45 KT 50 MPH...POST-TROPICAL 120H 24/0600Z 34.0N 22.0W 40 KT 45 MPH...POST-TROPICAL $$ FORECASTER AVILA |