000 WTNT42 KNHC 292039 TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 23 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 500 PM AST THU SEP 29 2011 PHILIPPE HAS BEEN A CONUNDRUM TODAY. THE LOW-LEVEL CIRCULATION HAS BEEN ELONGATED FOR MUCH OF THE DAY...AND RECENT MICROWAVE OVERPASSES HAVE SHOWN A WELL-DEFINED MID-LEVEL EYE WELL TO THE NORTH OF THE PREVIOUSLY ESTIMATED CENTER. IT APPEARS THAT THE LOW-LEVEL CENTER IS REFORMING FARTHER NORTH...BUT IT IS NOT YET CERTAIN HOW MUCH IT IS TUCKED UNDER THE DEEP CONVECTION. BECAUSE OF THE UNCERTAINTY IN CENTER LOCATION...DVORAK INTENSITY ESTIMATES RUN THE GAMUT FROM 35 TO 55 KT. THE INITIAL INTENSITY IS HELD AT 40 KT...BUT THAT COULD BE CONSERVATIVE ESPECIALLY IF THE CENTER CONTINUES TO REFORM OR GET PULLED FARTHER NORTH INTO THE CONVECTION. PHILIPPE HAS ABOUT 24 HOURS TO STRENGTHEN BEFORE NORTHERLY VERTICAL SHEAR INCREASES. HOWEVER...THE INTENSITY MODELS SUGGEST THAT PHILIPPE WILL BE ABLE TO WITHSTAND THE HOSTILE CONDITIONS AND THUS ONLY SHOW GRADUAL WEAKENING AFTER 48 HOURS. THE OFFICIAL FORECAST FOLLOWS THAT SCENARIO AND KEEPS PHILIPPE AS A TROPICAL CYCLONE FOR THE ENTIRE FORECAST PERIOD. GIVEN THE CENTER RELOCATION...THE INITIAL MOTION IS AN UNCERTAIN 310 DEGREES AT 11 KT. THERE HAS BEEN NO CHANGE IN THE FORECAST TRACK REASONING. PHILIPPE WILL CONTINUE TO BE STEERED NORTHWESTWARD FOR THE NEXT DAY OR SO AND THEN TURN WESTWARD BY DAY 3 AS IT COMES UNDER THE INFLUENCE OF A BUILDING RIDGE TO THE NORTH. THE WESTWARD MOTION SHOULD CONTINUE THROUGH DAY 5...ESPECIALLY AS PHILIPPE BECOMES A WEAKER SYSTEM AS IS STEERED BY THE LOW-LEVEL EASTERLY FLOW. THE TRACK GUIDANCE IS IN FAIRLY GOOD AGREEMENT...AND THERE ARE REALLY NO OUTLIERS IN THE SUITE OF MODELS. THEREFORE...LITTLE CHANGE WAS REQUIRED TO THE OFFICIAL FORECAST COMPARED WITH THE PREVIOUS ONE. FORECAST POSITIONS AND MAX WINDS INIT 29/2100Z 20.2N 43.6W 40 KT 45 MPH 12H 30/0600Z 21.4N 44.8W 45 KT 50 MPH 24H 30/1800Z 22.8N 46.6W 45 KT 50 MPH 36H 01/0600Z 23.8N 48.5W 45 KT 50 MPH 48H 01/1800Z 24.5N 50.2W 45 KT 50 MPH 72H 02/1800Z 25.0N 54.0W 40 KT 45 MPH 96H 03/1800Z 25.0N 58.5W 35 KT 40 MPH 120H 04/1800Z 24.5N 62.0W 35 KT 40 MPH $$ FORECASTER BERG