WDPN31 PGTW 250300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (IN-FA) WARNING NR 036// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 29.7N 122.9E INITIAL INTENSITY: 65 KTS GEOGRAPHIC REFERENCE: 116 NM SOUTHEAST OF SHANGHAI, CHINA MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 12 KTS SIGNIFICANT WAVE HEIGHT: 32 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS FEEDER BAND CONVECTIVE TOPS CONTINUED TO WARM UP AND UNRAVEL; HOWEVER THE CENTRAL DENSE OVERCAST FEATURE REMAINS INTACT AND MAINTAINED A LARGE 40NM RAGGED EYE. THE INITIAL INTENSITY IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE THAT WAS COINCIDED WITH AN LLC FEATURE IN A CMA COMPOSITE RADAR LOOP. THE INITIAL INTENSITY OF 65KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK FIXES TO REFLECT THE DETERIORATING CONVECTIVE STAGE BUT MAINTAINED THE TYPHOON INTENSITY. INITIAL WIND RADII BASIS: PERSISTENCE. CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS RJTD: T4.5 - 77 KTS RCTP: T4.0 - 65 KTS KNES: T4.0 - 65 KTS CIMSS ADT: 43 KTS AT 242340Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 5-10 KTS SST: 27-28 CELSIUS OUTFLOW: MODERATE POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TYPHOON 09W WILL TURN MORE WESTWARD AFTER TAU 12 AND MAKE LANDFALL JUST SOUTH OF SHANGHAI, TRACK INLAND, THEN RECURVE NORTHEASTWARD AFTER TAU 72 IF IT MAINTAINS ITS LOW LEVEL STRUCTURE. THE DEGRADING ENVIRONMENT CAUSED BY COOLING SSTS AND LAND INTERACTION WILL GRADUALLY THEN RAPIDLY WEAKEN THE SYSTEM DOWN TO 25KTS BY TAU 120 AS IT APPROACHES THE YELLOW SEA. MODEL DISCUSSION: NUMERICAL MODELS DIVERGE SIGNIFICANTLY AFTER LANDFALL, SPREADING OUT TO OVER 260NM BY TAU 72 THEN DIVERGE SIGNIFICANTLY AFTERWARD, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST UP TO TAU 72 ONLY. THE SPREAD NARROWS DOWN TO UNDER 200NM BY TAU 120 BUT ALONG-TRACK SPEEDS WIDELY VARY. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: LOW// NNNN