000 WTNT42 KNHC 020834 TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 33 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 500 AM AST SUN OCT 02 2011 SINCE THE ASCAT OVERPASS AROUND 0100 UTC...WHICH INDICATED THAT THE MAXIMUM WINDS OF PHILIPPE WERE NEAR 60 KT...THE OVERALL CLOUD PATTERN HAS NOT CHANGED SIGNIFICANTLY. THEREFORE...THE INITIAL INTENSITY IS HELD AT 60 KT. PHILIPPE IS A STRONGLY SHEARED TROPICAL STORM WITH THE LOW-LEVEL CENTER LOCATED NEAR THE WESTERN EDGE OF THE ASSOCIATED DEEP CONVECTION. LATEST MICROWAVE DATA INDICATE THE STRUCTURE OF THE INNER CORE...ALBEIT SHEARED...REMAINS FAIRLY WELL ORGANIZED. PHILIPPE IS GRADUALLY TURNING WESTWARD...AND THE LATEST INITIAL MOTION ESTIMATE IS 285/9. A GENERAL WESTWARD MOTION AT ABOUT THE SAME SPEED IS FORECAST DURING THE NEXT 48 HOURS AS THE STORM REMAINS ON THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE. IN THREE TO FOUR DAYS...A TURN TOWARD THE NORTH WITH A DECREASE IN FORWARD SPEED IS EXPECTED AS THE RIDGE WEAKENS. BEYOND THAT TIME...A NORTHEASTWARD MOTION IS FORECAST IN RESPONSE TO AN APPROACHING LARGE-SCALE TROUGH. THE OFFICIAL FORECAST HAS BEEN NUDGED TO THE LEFT THROUGHOUT THE PERIOD...TRENDING TOWARD THE MULTI-MODEL CONSENSUS. AS MENTIONED IN THE LAST FEW DISCUSSIONS... THERE REMAINS CONSIDERABLE UNCERTAINTY AT THE END OF THE FORECAST PERIOD AS THE SPREAD IN THE GUIDANCE IS GREATER THAN NORMAL. ALTHOUGH THE SHEAR IS ESTIMATED TO BE AROUND 40 KT...ACCORDING TO THE SHIPS MODEL...IT HAS YET TO CAUSE PHILIPPE TO WEAKEN. THE INTENSITY MODELS UNANIMOUSLY CALL FOR A GRADUAL WEAKENING DURING THE NEXT TWO TO THREE DAYS AS THE SHEAR REMAINS STRONG. AFTER THREE DAYS...HOWEVER...MOST OF THE GUIDANCE SHOWS PHILIPPE RESTRENGTHENING AS THE SHEAR DECREASES. IT SHOULD BE NOTED THAT... LIKE THE TRACK FORECAST...THE INTENSITY PREDICTION IS HIGHLY UNCERTAIN. THE STRENGTH OF PHILIPPE AT THE LATTER FORECAST TIMES APPEARS TO BE ASSOCIATED WITH HOW THE CYCLONE INTERACTS WITH THE APPROACHING TROUGH. THE ECMWF MODEL SHOWS A WEAK SYSTEM BECOMING ABSORBED ALONG THE FRONT BY DAY 5. ON THE OTHER HAND...THE GFDL MODEL SHOWS PHILIPPE STRENGTHENING TO A HURRICANE...PERHAPS DUE TO BAROCLINIC ENHANCEMENTS. FOR NOW...THE OFFICIAL FORECAST IS BETWEEN THE EXTREMES AND FOLLOWS THE OVERALL TREND IN THE GUIDANCE. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 25.6N 50.8W 60 KT 70 MPH 12H 02/1800Z 25.8N 52.4W 55 KT 65 MPH 24H 03/0600Z 25.7N 54.5W 50 KT 60 MPH 36H 03/1800Z 25.6N 56.7W 45 KT 50 MPH 48H 04/0600Z 25.6N 58.9W 45 KT 50 MPH 72H 05/0600Z 26.5N 61.4W 50 KT 60 MPH 96H 06/0600Z 28.5N 61.0W 55 KT 65 MPH 120H 07/0600Z 32.0N 56.5W 55 KT 65 MPH $$ FORECASTER CANGIALOSI