000 WTNT42 KNHC 291452 TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 22 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 AM AST THU SEP 29 2011 IT APPEARS THAT THE CENTER OF THE POSSIBLY ELONGATED CIRCULATION OF PHILIPPE IS LOCATED TO THE SOUTH OF A CIRCULAR BALL OF CONVECTION. CURRENT INTENSITY ESTIMATES FROM BOTH THE SUBJECTIVE AND OBJECTIVE TECHNIQUES ARE 45-55 KT...BUT THE LATEST FINAL-T NUMBERS ARE 35-45 KT. THE INITIAL INTENSITY IS THEREFORE HELD AT 40 KT. PHILIPPE IS EXPECTED TO BE IN A RELATIVELY LOW-SHEAR ENVIRONMENT FOR THE NEXT 24 HOURS OR SO...BUT WITH SUCH AN ILL-DEFINED CIRCULATION IT MAY BE DIFFICULT FOR THE CYCLONE TO INTENSIFY MUCH...IF AT ALL. BY 48 HOURS...PHILIPPE IS FORECAST TO BE BLASTED BY 30 KT OF NORTHERLY SHEAR ON THE WEST SIDE OF A DEEP LONGWAVE TROUGH...AND THAT SHOULD INDUCE SOME WEAKENING. ODDLY ENOUGH...MANY OF THE INTENSITY MODELS EITHER SHOW STRENGTHENING TO A HURRICANE OR VERY LITTLE WEAKENING DURING THE FORECAST PERIOD...WHICH IS WHY THE OFFICIAL FORECAST INDICATES ONLY GRADUAL WEAKENING EVEN IN THE FACE OF SEEMINGLY HOSTILE UPPER-LEVEL WINDS. IF PHILIPPE CAN SURVIVE ITS ENVIRONMENT...WHICH SO FAR IT HAS BEEN ABLE TO DO...THEN IT MAY BE ABLE TO HOLD ON AS A TROPICAL CYCLONE WHEN UPPER-LEVEL WINDS RELAX A BIT BETWEEN 96 AND 120 HOURS. PHILIPPE IS LOCATED ALONG THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL ANTICYCLONE AND IS MOVING 305 DEGREES AT 11 KT. AS THE CYCLONE CONTINUES NORTHWESTWARD DURING THE NEXT 36 HOURS...A SECOND STRONGER MID-LEVEL HIGH IS EXPECTED TO BUILD OVER THE SUBTROPICAL CENTRAL ATLANTIC. THIS SHOULD FORCE PHILIPPE ON A MORE WESTWARD COURSE THROUGH THE REMAINDER OF THE FORECAST PERIOD. THE TRACK GUIDANCE IS GENERAL AGREEMENT ON THIS SCENARIO...AND THE OFFICIAL FORECAST LIES A LITTLE TO THE NORTHEAST OF THE TVCA MODEL CONSENSUS IN THE DIRECTION OF THE GFS AND ECMWF THROUGH 48 HOURS...THEN SWITCHES TO A BIT SOUTH OF THE CONSENSUS FROM 96-120 HOURS. THIS FORECAST IS NOT APPRECIABLY DIFFERENT FROM THE PREVIOUS ONE. FORECAST POSITIONS AND MAX WINDS INIT 29/1500Z 18.6N 42.6W 40 KT 45 MPH 12H 30/0000Z 19.7N 43.9W 45 KT 50 MPH 24H 30/1200Z 21.1N 45.8W 45 KT 50 MPH 36H 01/0000Z 22.3N 47.8W 45 KT 50 MPH 48H 01/1200Z 23.1N 49.9W 45 KT 50 MPH 72H 02/1200Z 24.0N 53.5W 40 KT 45 MPH 96H 03/1200Z 24.5N 57.0W 35 KT 40 MPH 120H 04/1200Z 24.5N 60.5W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ FORECASTER BERG