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#464335 (Received by flhurricane at: 10:41 PM 05.Oct.2011) TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 48 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 PM AST WED OCT 05 2011 PHILIPPE HAS CHANGED LITTLE IN ORGANIZATION DURING THE PAST SEVERAL HOURS. THE LOW-LEVEL CENTER IS LOCATED NEAR THE WESTERN EDGE OF THE CENTRAL CONVECTION...WHILE AN OUTER CONVECTIVE BAND IS PRESENT IN THE EASTERN SEMICIRCLE. SATELLITE INTENSITY ESTIMATES REMAIN 65 KT FROM TAFB AND 55 KT FROM SAB...SO THE INITIAL INTENSITY REMAINS 55 KT. ANALYSES FROM THE SHIPS MODEL AND CIMSS AT THE UNIVERSITY OF WISCONSIN SHOW THAT THE VERTICAL WIND SHEAR HAS DECREASED TO ABOUT 10 KT. THE INITIAL MOTION IS NOW 010/6. PHILIPPE IS RECURVING TO THE EAST OF A DEEP-LAYER TROUGH AND ASSOCIATED SURFACE COLD FRONT OVER THE WESTERN ATLANTIC...AND THE TRACK GUIDANCE IS NOW IN GOOD AGREEMENT THAT THE CYCLONE WILL MOVE GENERALLY NORTHEASTWARD WITH SOME ACCELERATION DURING THE NEXT 5 DAYS. A MORE NORTHERLY MOTION MAY OCCUR AFTER 72 HOURS AS THE CYCLONE BECOMES EXTRATROPICAL AND MERGES WITH THE DEEP-LAYER TROUGH...AND THIS IS REFLECTED IN THE FORECAST TRACK. THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK AND LIES IN THE MIDDLE OF THE TRACK GUIDANCE ENVELOPE. WHILE PHILIPPE HAS NOT YET STRENGTHENED...THERE WILL BE A 12-24 HOUR PERIOD OF LIGHT TO MODERATE SHEAR BEFORE THE CYCLONE ENCOUNTERS THE STRONGER WESTERLIES TO THE NORTH. FOR THE MOST PART...THE INTENSITY GUIDANCE STILL CALLS FOR PHILIPPE TO BECOME A HURRICANE DURING THAT TIME...AND SO DOES THE INTENSITY FORECAST. AFTER 24 HOURS...INCREASING SHEAR SHOULD CAUSE A WEAKENING TREND. EXTRATROPICAL TRANSITION SHOULD BEGIN IN ABOUT 48 HOURS AND BE COMPLETE BY 72 HOURS. THE DYNAMICAL MODELS AGREE ON PHILIPPE MAINTAINING GALE TO STORM INTENSITY AS AN EXTRATROPICAL LOW...AND THIS IS REFLECTED IN THE INTENSITY FORECAST. FORECAST POSITIONS AND MAX WINDS INIT 06/0300Z 26.4N 61.0W 55 KT 65 MPH 12H 06/1200Z 27.4N 60.4W 60 KT 70 MPH 24H 07/0000Z 28.5N 58.8W 65 KT 75 MPH 36H 07/1200Z 29.3N 56.5W 60 KT 70 MPH 48H 08/0000Z 30.8N 53.1W 55 KT 65 MPH 72H 09/0000Z 37.0N 45.5W 55 KT 65 MPH...POST-TROP/EXTRATROP 96H 10/0000Z 43.5N 41.5W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 11/0000Z 52.0N 33.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER BEVEN |