MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (DOLPHIN) WARNING NR 011// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 14W (DOLPHIN), LOCATED APPROXIMATELY 256 NM SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHEASTWARD AT 20 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) REVEALS AN OBSCURED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION LOCATED OVERHEAD AND SHEARED OVER THE NORTHEAST QUADRANT. A 230017Z ASCAT-A IMAGE DEPICTS HIGHER WINDS (50 KTS) LOCATED TO THE NORTH OF AN ELONGATED LLCC. THE INITIAL INTENSITY IS ASSESSED AT 50 KTS BASED ON DVORAK CURRENT INTENSITY ESTIMATES OF T3.0-3.5 (45-55 KTS), A 232340Z ADVANCED DVORAK TECHNIQUE ESTIMATE OF T3.1 (47KTS), AND A 232211Z SATCON ESTIMATE OF 48 KTS. ALL WIND RADII HAVE BEEN UPDATED WITH RECENT ASCAT DATA. UPPER LEVEL ANALYSIS REVEALS HIGH (25-30 KT) VERTICAL WIND SHEAR BEING OFFSET BY WARM SEA SURFACE TEMPERATURES (SST) AND ROBUST POLEWARD OUTFLOW THAT IS BEING ENHANCED BY THE WESTERLIES TO THE NORTH. OVERALL, THIS PRESENTS AN OVERALL MARGINALLY FAVORABLE ENVIRONMENT FOR CONTINUED DEVELOPMENT AS HIGH SHEAR IMPACTS THE SYSTEM. DUE TO THE ELONGATED NATURE OF THE LLCC, WEAK TEMPERATURE GRADIENT, AND EXPANDING WIND FIELD, THIS SYSTEM IS CURRENTLY ASSESSED AS SUBTROPICAL. TS 14W IS TRACKING NORTHEASTWARD ALONG THE NORTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. IN THE NEAR TERM, TS 14W SHOULD TRACK NORTHEASTWARD THROUGH TAU 36 UNDER THE INFLUENCE OF THE STR. AFTERWARDS, IT WILL SHIFT TO A NORTH-NORTHEASTWARD TRACK AS THE SYSTEM BECOMES EMBEDDED IN THE JET FLOW. AROUND TAU 24, TS 14W IS EXPECTED TO BEGIN EXTRATROPICAL TRANSITION AS BAROCLINICITY INCREASES AND THE SYSTEM STARTS TO GAIN FRONTAL CHARACTERISTICS AS IT APPROACHES A DEEPENING MIDLATITUDE TROUGH. AROUND THIS TIME, INCREASING VERTICAL WIND SHEAR (>40 KTS) WILL BE IMPACTING THE SYSTEM AS WELL. EXTRATROPICAL TRANSITIONS COMPLETION IS EXPECTED BY TAU 36 AS THE 1000-500 MB THICKNESS FIELDS SHOW A FRONTAL SYSTEM. AFTERWARDS, TS 14W SHOULD TRACK NORTH- NORTHEASTWARD AS AN EXTRATROPICAL LOW. NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU 36 AND THEN SLOWLY DIVERGES TO 80 NM SPREAD AT TAU 48 AND 150 NM BY TAU 72. THE 22/18Z ECMWF ENSEMBLE SOLUTIONS REMAIN IN GOOD AGREEMENT AND DEPICT PASSAGE EAST OF HONSHU. PLACED NEAR THE ECMWF SOLUTION AND THE MULTI-MODEL CONSENSUS, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN