000 WTNT42 KNHC 261434 TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 AM AST MON SEP 26 2011 DEEP CONVECTION HAS BEEN PULSING...BUT OVERALL THE CLOUD PATTERN OF PHILIPPE HAS NOT CHANGED SIGNIFICANTLY OVER THE PAST SEVERAL HOURS. MOST OF THE SHOWERS AND THUNDERSTORMS HAVE BEEN OCCURRING OVER THE SOUTHERN PORTION OF THE CIRCULATION. DVORAK CURRENT INTENSITY ESTIMATES FROM TAFB AND SAB ARE UNCHANGED...AND THE INITIAL INTENSITY IS HELD AT 50 KT. THE STORM IS BEING AFFECTED BY MODERATE WESTERLY SHEAR AND THE UPPER-LEVEL OUTFLOW IS RESTRICTED OVER THE NORTHWEST QUADRANT. SINCE THE SHEAR IS NOT FORECAST TO DIMINISH...ONLY SLIGHT SHORT-TERM STRENGTHENING SEEMS POSSIBLE. WATER VAPOR IMAGERY SHOWS INCREASING WESTERLY FLOW NORTH OF 20N AND...IF THIS FLOW PERSISTS...PHILIPPE WILL BE MOVING INTO A MORE HOSTILE ENVIRONMENT IN A COUPLE OF DAYS. THE OFFICIAL WIND SPEED FORECAST IS CONSERVATIVE AND ONLY SHOWS SLIGHT WEAKENING AFTER 24 HOURS...CLOSE TO THE LATEST LGEM GUIDANCE. IT IS POSSIBLE... HOWEVER...THAT THE CYCLONE COULD WEAKEN MORE THAN SHOWN HERE IN THE LATTER PART OF THE FORECAST PERIOD. PHILIPPE APPEARS TO HAVE TURNED SLIGHTLY TO THE RIGHT AND THE MOTION ESTIMATE IS NOW 310/10. THE STORM SHOULD MOVE ALONG THE SOUTHWESTERN AND WESTERN PERIPHERY OF A MID-LEVEL ANTICYCLONE OVER THE NEXT FEW DAYS. BY DAYS 4 AND 5...AS A LARGE TROUGH AMPLIFIES OVER THE EASTERN ATLANTIC NORTH OF 30N...MOST OF THE TRACK MODELS TURN PHILIPPE SHARPLY TOWARD THE NORTHEAST. THE ECMWF MODEL...WHICH DEPICTS A WEAKER CYCLONE...IS AN OUTLIER IN THAT IT FORECASTS PHILIPPE TO MOVE NORTHWESTWARD TO WEST-NORTHWESTWARD THROUGH THE PERIOD. SINCE THE CYCLONE COULD WEAKEN MORE THAN EXPECTED...THE LATTER SCENARIO IS INDEED PLAUSIBLE. FOR NOW...THE OFFICIAL FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS TRACK. FORECAST POSITIONS AND MAX WINDS INIT 26/1500Z 15.2N 34.2W 50 KT 60 MPH 12H 27/0000Z 16.0N 35.1W 55 KT 65 MPH 24H 27/1200Z 17.0N 36.1W 55 KT 65 MPH 36H 28/0000Z 18.0N 37.1W 50 KT 60 MPH 48H 28/1200Z 19.1N 38.2W 50 KT 60 MPH 72H 29/1200Z 22.0N 40.0W 50 KT 60 MPH 96H 30/1200Z 24.5N 40.0W 45 KT 50 MPH 120H 01/1200Z 26.0N 39.0W 45 KT 50 MPH $$ FORECASTER PASCH