WDPN32 PGTW 141500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (RAMMASUN) WARNING NR 17// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 09W (RAMMASUN), LOCATED APPROXIMATELY 435 NM EAST- SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) SHOWS TY 09W HAS SLOWED AND CONTINUED TO CONSOLIDATE AS CONVECTION HAS FURTHER DEEPENED AND HAS SINCE DEVELOPED AN IRREGULAR 15NM EYE. A 141044Z SSMIS 91GHZ MICROWAVE IMAGE ALSO SHOWS INCREASED STRENGTHENING AS THE EYEWALL STRUCTURE HAS BECOME MORE DEVELOPED AND AS CONVECTIVE BANDING ALONG THE SOUTHERN SEMI-CIRCLE HAS INCREASED. UPPER LEVEL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT AS VIGOROUS EQUATORWARD OUTFLOW CONTINUES WHILE VERTICAL WIND SHEAR (VWS) REMAINS AT LOW (05 TO 10 KNOTS) LEVELS. THE INITIAL POSITION IS BASED UPON THE IRREGULAR EYE FEATURE SEEN IN THE EIR LOOP WITH HIGH CONFIDENCE. THE CURRENT INTENSITY HAS BEEN INCREASED TO 75 KNOTS BASED ON THE INCREASED ORGANIZATION OBSERVED IN THE AFOREMENTIONED SATELLITE IMAGERY WHILE DVORAK INTENSITY ESTIMATES FROM PGTW AND RJTD HAVE INCREASED TO 77 KNOTS. TY 09W REMAINS ON A GENERALLY WESTWARD TRACK DESPITE A WEST- SOUTHWESTWARD DEFLECTION IN THE PAST 6 HOURS DUE TO A SLIGHT AMPLIFICATION IN THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) THAT IS ANCHORED TO THE NORTH OF THE SYSTEM. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 09W IS FORECAST TO CONTINUE WESTWARD FOR THE NEXT 12 HOURS ALONG THE SOUTHERN PERIPHERY OF THE ENTRENCHED STR. THE FAVORABLE UPPER LEVEL ENVIRONMENT AND CONDUCIVE SEA SURFACE TEMPERATURES (SST) WILL ALLOW FOR FURTHER INTENSIFICATION THROUGH THE NEXT 12 HOURS BEFORE THE SYSTEM BEGINS TO INTERACT WITH LAND AND MAKES LANDFALL JUST BEFORE TAU 24. AS THE SYSTEM TRACKS OVER LAND, A WEAKENING TREND IS EXPECTED THROUGH TAU 48 UNTIL THE SYSTEM RE-EMERGES IN THE SOUTH CHINA SEA. A SLIGHT REORIENTATION IN THE STR IS EXPECTED AFTER TAU 24 WHICH WILL SLIGHTLY TURN TY 09W TO THE WEST-NORTHWEST. AFTER TAU 48, THE SYSTEM IS FORECAST TO PROCEED FURTHER INTO THE MORE OPEN WATERS OF THE SOUTH CHINA SEA WHERE THE INCREASED DISTANCE TO LAND, FAVORABLE UPPER LEVEL SUPPORT AND WARM WATERS WILL CAUSE TY 09W TO START RE-INTENSIFYING. C. IN THE EXTENDED TAUS, THE SYSTEM IS FORECAST TO CONTINUE WEST- NORTHWESTWARD ACROSS THE SOUTH CHINA SEA TOWARDS NORTHERN HAINAN ISLAND, MAKING LANDFALL BETWEEN TAU 96 AND 120 ACROSS THE LUICHOW PENINSULA AND INTO MAINLAND CHINA. WARM SST, DECREASED VWS, AND INCREASED OUTFLOW IN THE SOUTH CHINA SEA WILL ALLOW FOR FURTHER INTENSIFICATION, REACHING 95 KNOTS PRIOR TO LANDFALL AND WEAKENING THEREAFTER DUE TO LAND INTERACTION. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH SOME SLIGHT DIFFERENCES IN TRACK SPEED BUT IS OTHERWISE TIGHTLY GROUPED. DUE TO THE OVERALL GOOD AGREEMENT IN THE MODELS, THERE IS NOW HIGH CONFIDENCE IN THE FORECAST TRACK. HOWEVER, THERE IS STILL SOME UNCERTAINTY IN THE INTENSITY FORECAST DUE TO THE EXTENT OF THE WEAKENING ANTICIPATED WITH THE LAND INTERACTION IN THE MID FORECAST.// NNNN