MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (FUNG-WONG) WARNING NR 10// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 16W (FUNG-WONG), LOCATED APPROXIMATELY 392 NM SOUTH-SOUTHWEST OF TAIPEI, TAIWAN, HAS TRACKED WEST-NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED DEEP CONVECTION THAT CONTINUES TO OBSCURE THE LOW LEVEL CIRCULATION CENTER. THE INITIAL POSITION IS BASED ON THE EIR LOOP AND ON A WARM SPOT ON THE 191718Z TRMM MICROWAVE IMAGE WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS AVERAGED FROM DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER-LEVEL ANALYSIS INDICATES THE STORM IS IN A NEUTRAL POINT JUST SOUTH OF THE RIDGE AXIS IN AN AREA OF LIGHT TO MODERATE (10 TO 15 KNOT) NORTHEASTERLY VERTICAL WIND SHEAR (VWS). HOWEVER, THE VWS IS OFFSET BY STRONG EQUATORWARD OUTFLOW THAT IS PROVIDING VENTILATION TO THE CONVECTION. THE CYCLONE IS CURRENTLY TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING. B. TS 16W IS EXPECTED TO ROUND THE WESTERN EDGE OF THE STR AND TRACK NORTH TO NORTH-NORTHEASTWARD OVER THE NEXT 12-24 HOURS AS AN APPROACHING SHORTWAVE TROUGH WEAKENS THE STEERING RIDGE. AFTER TAU 24, TS 16W WILL DRAG ACROSS THE WESTERN COAST OF TAIWAN BEFORE TURNING ON A MORE POLEWARD TRACK INTO THE EASTERN CHINESE SEABOARD AS THE STR BUILDS BACK. BY TAU 72, THE SYSTEM WILL BE WELL INLAND OVER EASTERN CHINA. LOW VWS AND GOOD EQUATORWARD OUTFLOW WILL ENHANCE INTENSIFICATION OVER THE NEXT 36 HOURS, PEAKING AT 50 KNOTS BEFORE LANDFALL INTO TAIWAN. AFTERWARDS, INCREASING VWS AND INTERACTION WITH THE RUGGED CHINESE TERRAIN WILL GRADUALLY ERODE THE SYSTEM DOWN TO 35 KNOTS BY TAU 72. C. AFTER TAU 72, TS FUNG-WONG WILL BE POISED TO EXIT THE CHINESE COAST JUST SOUTH OF SHANGHAI. A SECONDARY SHORTWAVE TROUGH WILL WEAKEN THE STR ANEW AND CAUSE THE CYCLONE TO RECURVE AND ACCELERATE NORTHEASTWARD. CONCURRENTLY, THE SYSTEM WILL BEGIN EXTRA-TROPICAL TRANSITION AND BY END OF FORECAST, WILL BE A COLD-CORE LOW JUST SOUTH OF BUSAN, SOUTH KOREA. THE COLD SEA SURFACE TEMPERATURES OF THE YELLOW SEA AND INCREASED VWS WILL REDUCE 16W TO A 25-KNOT SYSTEM. NUMERIC MODEL GUIDANCE IS IN FAIRLY TIGHT AGREEMENT OVER THE NEXT 48 HOURS, LENDING HIGH CONFIDENCE TO THE FIRST HALF OF THE JTWC FORECAST, AFTERWARDS, THE MODEL TRACKERS SPREAD OUT SIGNIFICANTLY; HOWEVER, THE MAJORITY OF WHICH PROJECT A NORTHEASTWARD RECURVATURE.// NNNN NNNN