MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (RAMMASUN) WARNING NR 14// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 09W (RAMMASUN), LOCATED APPROXIMATELY 668 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 19 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS DEEP CENTRALIZED CONVECTION CONTINUES TO FLARE AND WEAKEN OVER THE PAST 12 HOURS. THE OVERALL ORGANIZATION REMAINS POORLY DEFINED WITH A RECENT 131939Z SSMI PARTIAL PASS SHOWING THE DEEPEST CONVECTION IS LOCATED WITHIN THE WESTERN HALF OF THE LOW LEVEL CIRCULATION CENTER (LLCC). UPPER LEVEL ANALYSIS INDICATES MODERATE LEVELS OF VERTICAL WIND SHEAR (VWS) (10 TO 15 KNOTS) PERSISTS OVER THE LLCC. THE NORTHEASTERLY FLOW IS SUPPORTING GOOD OUTFLOW IN THE SOUTHWESTERN QUADRANT OF THE SYSTEM. THE CURRENT INTENSITY HAS BEEN INCREASED TO 40 KNOTS AS THE CONVECTION HAS BEEN IMPROVING, WITH DVORAK ESTIMATES ALSO SHOWING A STRENGTHENING TREND OVER THE PAST SIX HOURS. TS 09W IS QUICKLY TRACKING WEST ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) ANCHORED TO THE NORTH OF THE SYSTEM. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 09W IS FORECAST TO CONTINUE WESTWARD FOR THE NEXT 36 HOURS ALONG THE SOUTHERN PERIPHERY OF THE ENTRENCHED STR. LANDFALL INTO THE CENTRAL PHILIPPINES IS FORECAST FOR TAU 36, LEADING TO A SLIGHT WEAKENING TREND AS THE CIRCULATION CROSSES OVER SOUTHERN LUZON. AFTER THE SYSTEM MOVES INTO THE SOUTH CHINA SEA, AN IMPROVING ENVIRONMENT IN THE LOW LEVEL FLOW WITH MARGINAL UPPER LEVEL SUPPORT WILL CAUSE TS 09W TO START INTENSIFYING AS IT TRACKS MORE WEST-NORTHWESTWARD AROUND THE STR. C. IN THE EXTENDED TAUS, TS RAMMASUN IS EXPECTED TO CONTINUE TO TRACK WEST-NORTHWESTWARD ACROSS THE SOUTH CHINA SEA AND TOWARDS NORTHERN HAINAN ISLAND, MAKING LANDFALL JUST BEFORE TAU 120 INTO THE LUICHOW PENINSULA. WARM SEA SURFACE TEMPERATURES, DECREASED VWS, AND INCREASED OUTFLOW IN THE SOUTH CHINA SEA WILL ALLOW FOR RE- INTENSIFICATION REACHING 80 KNOTS PRIOR TO LANDFALL. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH SOME DIFFERENCES IN TRACK SPEED BUT IS OTHERWISE TIGHTLY GROUPED. DUE TO THE LOW CONFIDENCE IN THE INITIAL POSITION AND THE UNCERTAINTY IN THE TRANSLATIONAL SPEED, THE CONFIDENCE IN THE FORECAST REMAINS LOW.// NNNN NNNN