000 WTNT42 KNHC 021444 TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 34 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 AM AST SUN OCT 02 2011 PHILIPPE HAS BECOME AN EXPOSED SWIRL OF LOW CLOUDS ACCOMPANIED BY A SHRINKING AREA OF DEEP CONVECTION TO THE SOUTHEAST...AND IT ONLY TOOK 30-40 KT OF SHEAR TO MAKE THAT HAPPEN. DVORAK CURRENT INTENSITY NUMBERS ARE 3.0...OR 45 KT...FROM TAFB AND SAB. IN ADDITION...VARIOUS SATELLITE PRODUCTS FROM THE CIMSS GROUP AT THE UNIVERSITY OF WISCONSIN ARE PROVIDING ESTIMATES BETWEEN 40 AND 45 KT. THE INITIAL INTENSITY IS THEREFORE LOWERED TO 45 KT ON THIS ADVISORY. AS THE DEEP CONVECTION BECAME SHEARED OFF TO THE SOUTHEAST EARLIER THIS MORNING...THE LOW-LEVEL CENTER APPEARED TO MAKE A JOG TO THE NORTHWEST. THE 12-HOUR SMOOTHED MOTION IS 295 DEGREES AT 10 KT. THE TRACK GUIDANCE CONTINUES TO AGREE ON A WESTWARD MOTION DURING THE NEXT 48 HOURS AS PHILIPPE IS STEERED BY A SUBTROPICAL HIGH TO ITS NORTH. THE CYCLONE REACHES A WEAKNESS IN THE RIDGE CREATED BY A MID- TO UPPER-LEVEL CUT-OFF LOW NEAR SOUTHEASTERN CANADA BY 72 HOURS...AND THIS SHOULD CAUSE IT TO TURN SLOWLY NORTH AND NORTHEASTWARD ON DAYS 3 AND 4. SOME ACCELERATION TO THE NORTHEAST IS FORECAST ON DAY 5 AS PHILIPPE BECOMES EMBEDDED IN DEEP-LAYER SOUTHWESTERLY FLOW. FOR THE FIRST 48 HOURS...THE OFFICIAL FORECAST IS NORTH OF THE MODEL CONSENSUS AND LEANS TOWARD THE BAM SHALLOW MODEL...WHICH SEEMS TO HAVE HAD A MORE ACCURATE MOTION RECENTLY. AFTER 72 HOURS...THE FORECAST SHOWS A WIDER AND FASTER RE-CURVATURE THAN THE CONSENSUS MODELS...AND THIS SCENARIO IS SUPPORTED BY THE ECMWF AND THE BAM SHALLOW AND MEDIUM MODELS. THE INTENSITY FORECAST REMAINS OF LOW CONFIDENCE. THE SHIPS GUIDANCE SUGGESTS THAT THE NORTHERLY VERTICAL SHEAR OVER PHILIPPE HAS PEAKED AND SHOULD GRADUALLY RELAX OVER THE NEXT 72 HOURS. SOME WEAKENING IS INDICATED IN THE OFFICIAL FORECAST DURING THAT PERIOD. TAKING IT A STEP FURTHER...THE ECMWF HAS BEEN FAIRLY CONSISTENT IN SHOWING PHILIPPE DISSIPATING AHEAD OF A FRONTAL BOUNDARY BY DAY 3. ALTHOUGH THAT IS A PLAUSIBLE SCENARIO...THE OFFICIAL FORECAST CONTINUES TO FOLLOW THE MAIN INTENSITY MODELS FOR NOW AND SHOWS THE POSSIBILITY OF SOME RE-STRENGTHENING ON DAYS 3 THROUGH 5. HOWEVER...IT IS NOT AS AGGRESSIVE AS THE GFDL...HWRF...AND FSU SUPERENSEMBLE...ALL OF WHICH INDICATE THAT PHILIPPE WILL BECOME A SIGNIFICANT HURRICANE. FORECAST POSITIONS AND MAX WINDS INIT 02/1500Z 26.3N 51.7W 45 KT 50 MPH 12H 03/0000Z 26.5N 53.4W 40 KT 45 MPH 24H 03/1200Z 26.3N 55.5W 35 KT 40 MPH 36H 04/0000Z 26.2N 57.7W 35 KT 40 MPH 48H 04/1200Z 26.3N 59.8W 35 KT 40 MPH 72H 05/1200Z 28.0N 62.0W 40 KT 45 MPH 96H 06/1200Z 30.0N 60.5W 50 KT 60 MPH 120H 07/1200Z 32.5N 56.0W 50 KT 60 MPH $$ FORECASTER BERG