MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (FAXAI) WARNING NR 018// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 14W (FAXAI), LOCATED APPROXIMATELY 601 NM EAST OF IWO TO, JAPAN, HAS TRACKED NORTHWESTWARD AT 17 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (AMSI) DEPICTS A LOW LEVEL CIRCULATION (LLC) UNDER THE ASSOCIATED DEEP CONVECTION. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE CURRENT AMSI LOOP. THE INITIAL INTENSITY OF 45 KTS IS BASED ON THE HIGH END OF AGENCY AND OBJECTIVE DVORAK ESTIMATES OF T2.5-T2.7 AND REFLECTS THE SLIGHT INTENSIFICATION OF THE SYSTEM. UPPER-LEVEL ANALYSIS DEPICTS A TUTT CELL LOCATED TO THE NORTHWEST AND TROUGHING SOUTHWARD OF THE SYSTEM. THIS ENVIRONMENT IS CAUSING STRONG SUBSIDENCE ALONG THE WESTERN PERIPHERY OF THE CYCLONE, THUS RESTRICTING WESTWARD OUTFLOW AND CONSTRAINING VERTICAL DEVELOPMENT. HOWEVER, MODERATE SOUTHEASTWARD OUTFLOW INTO ANOTHER TUTT CELL TO THE EAST PROVIDES VENTILATION TO THE CONVECTION. TS 14W HAS A FAVORABLE VERTICAL WIND SHEAR (VWS) ENVIRONMENT WITH VALUES OF 10-20 KTS AND CONTINUES TO TRACK OVER WARM SST (30 CELSIUS) WHILE A SUBTROPICAL RIDGE (STR) TO THE NORTH INFLUENCES THE STEERING. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 14W WILL MAINTAIN ITS CURRENT TRACK, STEERED BY THE STR. AFTER TAU 48, THE TRACK WILL TURN MORE NORTHWARD AS IT BEGINS TO ROUND THE STR AXIS. AROUND TAU 66, TS 14W WILL MAKE LANDFALL OVER HONSHU, JAPAN, NEAR TOKYO. THE FAVORABLE UPPER-LEVEL ENVIRONMENT WILL PROMOTE SLOW THEN RAPID INTENSIFICATION TO A PEAK INTENSITY OF 85 KTS BY TAU 48 AS THE SYSTEM CRESTS THE STR. THE POLEWARD OUTFLOW WILL INCREASE AS THE SYSTEM MOVES AWAY FROM THE INFLUENCE OF THE TUTT CELL AND TOWARDS PREVAILING WESTERLIES. TS 14W WILL WEAKEN TO 65 KTS AFTER LANDFALL. C. BEYOND TAU 72, TS 14W WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) AND ACCELERATE NORTHEASTWARD, EXITING BACK OVER THE PACIFIC OCEAN. THE SYSTEM WILL CONTINUE TO RAPIDLY DECAY DUE TO INCREASING VWS AND COOLING SST, TRANSFORMING INTO A STRONG GALE-FORCE COLD CORE LOW WITH AN EXPANDING WIND FIELD BY TAU 96. NUMERICAL MODELS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO ALL PORTIONS OF THE JTWC FORECAST TRACK.// NNNN NNNN