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#47594 (Received by flhurricane at: 10:28 PM 21.Sep.2005) TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 19 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT WED SEP 21 2005 PHILIPPE REMAINS QUITE DISORGANIZED AS IT REMAINS IN THE GRIP OF A LARGE UPPER-TROPOSPHERIC CYCLONE CENTERED ABOUT 300 N MI TO ITS WEST. CURRENT INTENSITY ESTIMATE IS A HIGHLY UNCERTAIN 40 KT. THE INTENSITY FORECAST REMAINS CHALLENGING. IF THE SHEARING INFLUENCE OF THE UPPER CYCLONE PERSISTS...THE SYSTEM WILL PROBABLY WEAKEN AND COULD EVEN DISSIPATE. HOWEVER THE GFS CONTINUES TO PREDICT THAT THE UPPER CYCLONE WILL WEAKEN AND A MORE FAVORABLE ANTICYCLONIC FLOW PATTERN WILL DEVELOP OVER PHILIPPE. IF THAT WERE TO VERIFY...THE SYSTEM COULD RESTRENGTHEN AS A TYPICAL TROPICAL CYCLONE. THERE IS ALSO THE POSSIBILITY OF A MORE HYBRID-TYPE OF STRENGTHENING IF THE SYSTEM CONTINUES TO INTERACT WITH THE UPPER CYCLONE. INDEED...THE SYSTEM ALREADY HAS SOMEWHAT OF A SUBTROPICAL APPEARANCE. GIVEN THE UNCERTAINTIES...THE OFFICIAL FORECAST ONLY SHOWS SLIGHT RESTRENGTHENING. EXTRATROPICAL TRANSFORMATION IS LIKELY TO OCCUR IN 4-5 DAYS. THE CENTER IS PRACTICALLY IMPOSSIBLE TO FIND WITHOUT VISIBLE IMAGES...SO THE INITIAL MOTION...360/10...IS EXTREMELY UNCERTAIN. DYNAMICAL TRACK GUIDANCE CONTINUES TO AGREE ON A NORTHWARD TO NORTH-NORTHWESTWARD MOTION ON THE WESTERN SIDE OF A SUBTROPICAL ANTICYCLONE FOR THE NEXT 48 HOURS OR SO. THEREAFTER...A STRONG SHORTWAVE TROUGH MOVING OFF THE CANADIAN MARITIMES SHOULD ASSIST RECURVATURE INTO THE WESTERLIES...WITH ACCELERATION. THE GFS CONTINUES TO SHOW ONLY A PORTION OF PHILIPPE GETTING PICKED UP BY THE TROUGH. THE CURRENT NHC TRACK FORECAST IS A LITTLE SLOWER THAN THE PREVIOUS ONE AT DAYS 3-5...ONLY BECAUSE OF A SLIGHT UNCERTAINTY WHETHER THE SYSTEM WILL BE FULLY PICKED UP BY THE TROUGH. FORECASTER PASCH FORECAST POSITIONS AND MAX WINDS INITIAL 22/0300Z 22.4N 57.0W 40 KT 12HR VT 22/1200Z 24.2N 57.3W 40 KT 24HR VT 23/0000Z 26.6N 58.0W 45 KT 36HR VT 23/1200Z 29.2N 58.8W 50 KT 48HR VT 24/0000Z 31.7N 59.3W 50 KT 72HR VT 25/0000Z 35.5N 55.0W 45 KT 96HR VT 26/0000Z 38.5N 49.0W 40 KT 120HR VT 27/0000Z 42.0N 40.0W 40 KT...EXTRATROPICAL |