MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (FAXAI) WARNING NR 15// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 14W (FAXAI), LOCATED APPROXIMATELY 820 NM EAST-SOUTHEAST OF IWO TO, HAS TRACKED NORTHWESTWARD AT 10 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL IMAGERY (AMSI) SHOWS THE LOW-LEVEL CIRCULATION (LLC) HAS MOVED BENEATH DEEP CONVECTION. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON RAIN BANDS WRAPPING UNDER THE SYSTEM IN THE AMSI. THE INITIAL INTENSITY OF 35 KTS IS BASED ON THE DVORAK ESTIMATE OF T2.5/35KTS FROM PGTW. UPPER-LEVEL ANALYSIS MAINTAINS A TUTT CELL TO THE NORTHWEST AND TROUGHING TO THE SOUTH OF TS 14W. THESE FEATURES ARE CAUSING STRONG SUBSIDENCE ALONG THE WESTERN PERIPHERY OF THE CYCLONE, WHICH CONSEQUENTLY IS RESTRICTING WESTWARD OUTFLOW AND INHIBITING VERTICAL DEVELOPMENT. HOWEVER, MODERATE SOUTHEASTWARD OUTFLOW INTO ANOTHER TUTT CELL LOCATED TO THE EAST PROVIDES VENTILATION FOR THE SYSTEM. TS 14W REMAINS IN AN AREA OF FAVORABLE (5-15 KTS) VERTICAL WIND SHEAR (VWS) AND WARM (30 CELSIUS) SEA SURFACE TEMPERATURE (SST). A SUBTROPICAL RIDGE (STR) CONTINUES TO STEER TS 14W TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 14W WILL CONTINUE ON ITS CURRENT TRACK, STEERED BY THE STR. AFTER TAU 48, THE TRACK WILL TURN MORE NORTHWESTWARD AS IT BEGINS TO ROUND THE STR AXIS. AROUND TAU 72, TS 14W WILL CREST THE STR AXIS NORTH OF IWO TO. THE FAVORABLE ENVIRONMENT WILL ALLOW INTENSIFICATION TO PEAK AT 90 KTS BY TAU 72 WHILE POLEWARD OUTFLOW INCREASES AS THE SYSTEM MOVES AWAY FROM THE INFLUENCE OF THE TUTT CELL AND TOWARD THE PREVAILING WESTERLIES. NUMERICAL MODELS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK. C. BEYOND TAU 72, TS 14W WILL TRACK NORTHWARD TOWARD JAPAN ON THE POLEWARD SIDE OF THE STR AXIS, MAKING LANDFALL AROUND TAU 84 OVER HONSHU SOUTHWEST OF TOKYO. UPON LANDFALL, THE SYSTEM WILL BEGIN TO ERODE AS VWS VALUES INCREASE AND LAND INTERACTION DECREASES INTENSITY TO 55 KTS BY TAU 96. AFTER TAU 96, TS 14W WILL BEGIN EXTRA- TROPICAL TRANSITION (ETT) AS IT ACCELERATES NORTHEASTWARD ACROSS THE KANTO PLAIN, EXITING BACK OVER THE PACIFIC OCEAN BEFORE COMPLETING ETT. THERE IS FAIR CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC TRACK FORECAST DUE TO UNCERTAINTY IN THE TIMING OF THE RECURVE AND TRACK SPEED OVER LAND.// NNNN NNNN