MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (DOLPHIN) WARNING NR 014// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 14W (DOLPHIN), LOCATED APPROXIMATELY 168 NM SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHEASTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY INDICATES ERODING DEEP CONVECTION SHEARING EASTWARD DUE TO STRONG (40KTS+) WESTERLY VERTICAL WIND SHEAR (VWS), PARTLY EXPOSING A RAGGED AND ELONGATED LOW LEVEL CIRCULATION (LLC). THIS IS CORROBORATED BY A 231629Z AMSR MICROWAVE PASS. THE EIR LOOP ALSO INDICATES THE FORMATION OF A FRONTAL BOUNDARY ALONG THE NORTHEAST PERIPHERY. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE PARTLY EXPOSED LLC IN THE EIR AND MICROWAVE IMAGES. THE INITIAL INTENSITY OF 45KTS IS BASED ON OVERALL ASSESSMENT OF AGENCY AND OBJECTIVE DVORAK ESTIMATES RANGING FROM T2.5/35KTS TO T3.5/55KTS AND REFLECTS THE DEGRADED STATUS OF THE SYSTEM. ANALYSES INDICATE THIS ASYMMETRIC HYBRID (SUBTROPICAL) SYSTEM IS EMBEDDED WITHIN THE PREVAILING WESTERLIES WITH INCREASING BAROCLINICITY. HOWEVER, THE SYSTEM HAS MAINTAINED A GOOD POLEWARD OUTFLOW CHANNEL AND WARM (28C) SST VALUES TO PARTIALLY OFFSET THE STRONG VWS. TS 14W IS TRACKING ALONG THE NORTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE EAST-SOUTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS DOLPHIN WILL CONTINUE ON ITS CURRENT TRACK UNDER THE STEERING STR. AFTER TAU 12, IT WILL TURN MORE POLEWARD AS THE STR BUILDS AND REORIENTS. INCREASING VWS WILL OFFSET THE STRONG POLEWARD OUTFLOW AND WARM SSTS AND GRADUALLY WEAKEN THE SYSTEM DOWN TO 35KTS BY TAU 24. CONCURRENTLY, TS 14W HAS BEGUN EXTRA-TROPICAL TRANSITION AND BY TAU 24, WILL TRANSFORM INTO A STORM-FORCE COLD CORE LOW WITH FRONTAL CHARACTERISTICS DEEP IN THE BAROCLINIC ZONE. NUMERICAL MODELS ARE IN TIGHT AGREEMENT THROUGH THE FORECAST PERIOD WITH AFUM AND ECMWF AS LEFT-OF-TRACK OUTLIERS. THERE IS HIGH CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID JUST RIGHT OF CONSENSUS TO OFFSET THE MODEL OUTLIERS.// NNNN NNNN