000 WTNT42 KNHC 030247 TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 36 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 PM AST SUN OCT 02 2011 BURSTS OF DEEP CONVECTION CONTINUE TO FORM NEAR THE WELL-DEFINED CENTER OF PHILIPPE. HOWEVER...THE CONVECTION HAS BEEN UNABLE TO SUSTAIN ITSELF IN THE FACE OF VERY STRONG UPPER-LEVEL WINDS FROM THE NORTH. PHILIPPE MAY BE SOMEWHAT RESILIENT IN SPITE OF THE SHEAR BECAUSE THE SHEAR IS CONFINED TO LEVELS ABOVE 300 MB INSTEAD OF EXTENDING THROUGH THE DEPTH OF THE TROPOSPHERE. A BLEND OF DVORAK T- AND CI-NUMBERS AND RECENT ADT VALUES SUGGESTS THAT PHILIPPE IS MAINTAINING ITS STRENGTH...AND THE INTENSITY IS HELD AT 45 KT. THE HOSTILE SHEAR AFFECTING PHILIPPE IS FORECAST TO GRADUALLY RELAX DURING THE NEXT COUPLE OF DAYS...REACHING A RELATIVE MINIMUM IN 48-72 HOURS. THE OFFICIAL FORECAST SHOWS WEAKENING OVER THE NEXT DAY OR SO UNTIL THE SHEAR WEAKENS...WITH SOME INTENSIFICATION EXPECTED IN 2 TO 3 DAYS. AFTER THAT...INCREASING SOUTHWESTERLY SHEAR...PERHAPS EVEN STRONGER THAN WHAT PHILIPPE IS EXPERIENCING NOW...SHOULD RESULT IN WEAKENING. THE OFFICIAL INTENSITY FORECAST IS NEAR THE INTENSITY CONSENSUS THROUGH DAY 3 BUT REMAINS A TAD BELOW IT AT LATER TIMES. IT SHOULD BE NOTED THAT THE ECMWF SOLUTION THAT CONTINUES TO INDICATE DISSIPATION IN 2-3 DAYS WHEN THE SHEAR IS FORECAST TO DECREASE HAS BEEN DISCOUNTED. RECENT FIXES INDICATE THAT PHILIPPE HAS CHANGED ITS HEADING. WHILE THE INITIAL MOTION ESTIMATE IS 270/10...RECENT SATELLITE IMAGES SUGGEST THAT A MOTION JUST SOUTH OF DUE WEST MAY HAVE ALREADY BEGUN. GLOBAL MODELS KEEP PHILIPPE MOVING WESTWARD TO EVEN WEST- SOUTHWESTWARD FOR THE NEXT DAY OR TWO TO THE SOUTH OF A MID-LEVEL RIDGE OVER THE CENTRAL ATLANTIC. LATER IN THE FORECAST PERIOD... PHILIPPE SHOULD TURN NORTHWARD AND EVENTUALLY NORTHEASTWARD UNDER THE INFLUENCE OF INCREASING WESTERLY FLOW TO SOUTH OF A MID- TO UPPER-LEVEL TROUGH OVER THE WEST-CENTRAL ATLANTIC. WHILE THE LARGE- SCALE MODELS ARE IN GOOD AGREEMENT ON THIS SCENARIO...DIFFERENCES ARE SEEN IN THE SHARPNESS AND TIMING OF THE TURN. THESE DIFFERENCES ARE LARGELY RELATED TO THE LATITUDE OF THE STORM WHEN IT FIRST ENCOUNTERS THIS DEEP-LAYER WESTERLY FLOW. THE UKMET AND NOGAPS... WHICH KEEP THE PHILIPPE FARTHER NORTH...FAVOR A QUICKER AND SHARPER TURN WHILE THE GFS AND REGIONAL MODELS...WHICH LIE FARTHER SOUTH INITIALLY...DELAY THE TURN AND ARE NOT AS SHARP. THE NEW NHC TRACK FORECAST IS NEAR THE MULTI-MODEL CONSENSUS AND GIVE THE MORE SOUTHERLY GROUP OF GUIDANCE GREATER WEIGHT GIVEN RECENT TRENDS IN THE OBSERVED MOTION. FORECAST POSITIONS AND MAX WINDS INIT 03/0300Z 26.1N 53.9W 45 KT 50 MPH 12H 03/1200Z 25.9N 55.6W 40 KT 45 MPH 24H 04/0000Z 25.6N 58.0W 40 KT 45 MPH 36H 04/1200Z 25.5N 60.1W 35 KT 40 MPH 48H 05/0000Z 26.1N 61.3W 40 KT 45 MPH 72H 06/0000Z 27.8N 61.3W 50 KT 60 MPH 96H 07/0000Z 30.2N 58.5W 45 KT 50 MPH 120H 08/0000Z 32.0N 55.0W 40 KT 45 MPH $$ FORECASTER KIMBERLAIN