WDPN32 PGTW 201500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (TRAMI) WARNING NR 15// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 12W (TRAMI), LOCATED APPROXIMATELY 211 NM SOUTH-SOUTHWEST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE CONVECTIVE BANDS, MOSTLY OVER AND ALONG THE SOUTHERN PERIPHERY OF THE LOW-LEVEL CIRCULATION CENTER (LLCC) HAS DEEPENED EVEN AS SUBSIDENCE CONTINUE TO IMPACT THE NORTHERN RIM OF THE SYSTEM. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION AND ON A RADAR COMPOSITE LOOP FROM THE TAIWAN CENTRAL WEATHER BUREAU. THE CURRENT INTENSITY OF 60 KNOTS IS AVERAGED FROM THE DVORAK ESTIMATES FROM PGTW, RJTD, AND KNES. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS APPROXIMATELY 07 DEGREES SOUTH OF A RIDGE AXIS IN AN AREA OF MODERATE (20-KNOT) NORTHEASTERLY VERTICAL WIND SHEAR (VWS). HOWEVER, A STRONG WESTWARD-EQUATORWARD OUTFLOW IS OFFSETTING THE VWS AND SUSTAINING THE ASSOCIATED DEEP CONVECTION. TS 12W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) ORIENTED ACROSS THE EAST CHINA SEA INTO WESTERN JAPAN. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TS TRAMI IS EXPECTED TO CONTINUE TRACKING WESTWARD UNDER THE STEERING INFLUENCE OF THE STR. THE STORM WILL SLIGHTLY INTENSIFY OVER THE NEXT 12 HOURS AS THE OUTFLOW INCREASES AND SEA SURFACE TEMPERATURES (SSTS) REMAIN WARM. AFTERWARDS, COOLING SSTS, LAND INTERACTION WITH NORTHERN TAIWAN, AND FINAL LANDFALL INTO CHINA WILL CAUSE ITS GRADUAL DECAY AND EVENTUAL DISSIPATION INLAND. DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST THAT IS LAID CLOSE TO MODEL CONSENSUS. // NNNN