000 WTNT42 KNHC 051456 TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 46 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 AM AST WED OCT 05 2011 PERSISTENT PHILIPPE CONTINUES AS A SHEARED TROPICAL CYCLONE WITH VERY COLD CLOUD TOPS AND FREQUENT LIGHTNING ON THE DOWNSHEAR...OR SOUTHEAST...SIDE OF THE CENTER. INTENSITY ESTIMATES RANGE FROM 40 KT FROM AN 0839Z AMSU CIMSS ANALYSIS ON THE LOW END TO 55 KT FROM THE TAFB DVORAK CURRENT INTENSITY NUMBER ON THE HIGH END. 55 KT IS RETAINED AS THE INITIAL INTENSITY...THOUGH THIS COULD BE SLIGHTLY GENEROUS. THE 34 KT WIND RADII WAS ADJUSTED OUTWARD SOME BASED UPON THE 0839Z AMSU CIRA SIZE ANALYSIS. A PAIR OF MICROWAVE IMAGES FROM FNMOC JUST BEFORE SYNOPTIC TIME ALLOWS FOR A FAIRLY ACCURATE INITIAL POSITION. BASED UPON THIS AND THE FIRST VISIBLE IMAGES THIS MORNING THAT SUGGEST THAT THE CENTER IS JUST TUCKED IN UNDERNEATH THE OVERCAST...AN INITIAL MOTION OF 310/5 IS ANALYZED. THE CYCLONE IS ROUNDING THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYER RIDGE AND RECURVATURE SHOULD COMMENCE SHORTLY. THE GLOBAL AND HURRICANE REGIONAL MODELS ARE IN GOOD AGREEMENT THAT A STRONG MID-LATITUDE TROUGH WILL TURN PHILIPPE TOWARD THE NORTHEAST BY TOMORROW WITH INCREASING FORWARD SPEED. THE TRACK FORECAST IS BASED UPON THE HURRICANE FORECAST IMPROVEMENT PROGRAM MULTI-MODEL CONSENSUS AND IS NEARLY THE SAME AS THE PREVIOUS ADVISORY. PHILIPPE HAS A SHORT WINDOW OF OPPORTUNITY TO BECOME A HURRICANE. THE WATER TEMPERATURES SHOULD REMAIN A WARM 28C UNDER THE TRACK OF THE CYCLONE FOR THE NEXT TWO TO THREE DAYS. HOWEVER...THE SYSTEM HAS ONLY ABOUT 24 HOURS OF MODERATE VERTICAL SHEAR BEFORE THE AFOREMENTIONED TROUGH CAUSES THE SHEAR TO INCREASE DRAMATICALLY. ADDITIONALLY...PHILIPPE IS SURROUNDED BY QUITE DRY AIR AS SHOWN IN THE TOTAL PRECIPITABLE WATER IMAGERY...THOUGH NOT MUCH OF THAT MAY ACTUALLY BE REACHING THE CENTER OF THE STORM. THE INTENSITY GUIDANCE IS QUITE DIVERSE WITH LGEM AND SHIPS STATISTICAL MODELS SHOWING LITTLE TO NO INTENSIFICATION...WHILE THE GFDL AND HWRF DYNAMICAL MODELS ARE MUCH MORE AGGRESSIVE IN SPINNING UP THE CYCLONE. THE INTENSITY FORECAST IS CLOSE TO THE HFIP IV15 CONSENSUS THROUGH TWO DAYS AND THEN NEAREST TO THE SHIPS MODEL THEREAFTER...WITH LITTLE CHANGE FROM THAT INDICATED IN THE PREVIOUS ADVISORY. EXTRATROPICAL TRANSITION IS UNANIMOUS BY ALL OF THE DYNAMICAL GUIDANCE TO OCCUR BY 72 HOURS...WHICH IS WHEN THE OFFICIAL FORECAST SHOWS THE TRANSITION. AN 120 HOUR POINT IS INCLUDED HERE AS ALL OF THE GUIDANCE...WITH THE PROMINENT EXCEPTION OF THE ECWMF WHICH KILLS OFF THE STORM AFTER 72 HOURS... CONTINUES PHILIPPE AS AN EXTRATROPICAL SYSTEM THROUGH AT LEAST FIVE DAYS. THE OCEAN PREDICTION CENTER PROVIDED TRACK AND INTENSITY GUIDANCE AT DAYS FOUR AND FIVE. FORECAST POSITIONS AND MAX WINDS INIT 05/1500Z 25.3N 61.3W 55 KT 65 MPH 12H 06/0000Z 26.0N 61.6W 60 KT 70 MPH 24H 06/1200Z 27.0N 60.8W 65 KT 75 MPH 36H 07/0000Z 28.2N 59.5W 60 KT 70 MPH 48H 07/1200Z 29.3N 57.0W 55 KT 65 MPH 72H 08/1200Z 34.0N 50.0W 55 KT 65 MPH 96H 09/1200Z 40.5N 45.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 10/1200Z 46.0N 38.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER LANDSEA/BROWN