WDPN31 PGTW 310900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 12W (HINNAMNOR) WARNING NR 013// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 25.4N 129.0E INITIAL INTENSITY: 130 KTS GEOGRAPHIC REFERENCE: 92 NM SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 13 KTS SIGNIFICANT WAVE HEIGHT: 48 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A WELL ORGANIZED SYSTEM WITH TIGHTLY WRAPPING CLOUD LINES FORMING AROUND AN 8NM EYE. A 310453Z AMSR2 89GHZ COLOR COMPOSITE MICROWAVE IMAGE INDICATES THAT 12W IS UNDERGOING AN EYE WALL REPLACEMENT CYCLE SHOWING A WELL DEFINED INNER EYEWALL, A SIZEABLE MOAT AND SECONDARY EYEWALL ABOUT 20NM OUT FROM THE CENTER. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON MSI AND AMSR2 MICROWAVE IMAGERY. THE INITIAL INTENSITY OF 130 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON ALL AGENCY DVORAK INTENSITY ESTIMATES SHOWING T6.5 AND CIMSS SATCON SHOWING 132KTS. FURTHERMORE, BASED ON THE ONGOING ERC, WE WOULD EXPECT SOME LEVEL OF WEAKENING AS THIS PROCESS DEVELOPS. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A MID TO UPPER-LEVEL RIDGE. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T6.5 - 127 KTS RJTD: T6.5 - 127 KTS KNES: T6.5 - 127 KTS CIMSS SATCON: 132 KTS AT 310102Z CIMSS ADT: 122 KTS AT 310540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 30-31 CELSIUS OUTFLOW: STRONG RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: STY 12W IS CURRENTLY TRACKING WEST-SOUTHWESTWARD UNDER THE DIMINISHING INFLUENCE OF A STR TO THE NORTHEAST. THROUGH TAU 36, 12W WILL EVENTUALLY BE TRACKING GENERALLY SOUTHWESTWARD IN A COMPETING STEERING ENVIRONMENT, ALL THE WHILE 13W WHICH IS ATTEMPTING TO DEVELOP TO ITS SOUTH WILL INCREASES ITS INTERACTION WITH 12W FURTHER EXACERBATING ITS ERRATIC MOVEMENT. AFTER TAU 36, 12W FINDS ITSELF IN A NEAR QUASI-STATIONARY ENVIRONMENT TRAPPED BETWEEN COMPETING RIDGES TO THE WEST AND EAST, AND A NEAR EQUATORIAL RIDGE (NER) BUILDING IN TO THE SOUTH, THIS COUPLED WITH ONGOING ERC AND INCREASING SHEAR WILL STEADILY WEAKEN THE SYSTEM. IN THIS ENVIRONMENT UPWELLING OF COOLER WATER WILL ALSO HAVE A MAJOR IMPACT ON THE SYSTEMS INTENSITY. NEAR TAU 48, A MID-LATITUDE SHORTWAVE TROUGH WILL BEGIN TO DEVELOP OVER NORTHWEST CHINA, AND BEGIN TO ERODE THE WESTERN RIDGE, MEANWHILE THE ENHANCED SOUTHWEST MONSOONAL FLOW WILL BUILD A STRONG RIDGE TO THE NORTHEAST OF THE SYSTEM. THESE TWO FACTORS COALESCE AND FORCE 12W TO MOVE GENERALLY NORTHWARD. AS TRACK SPEEDS INCREASE THERE IS NOTABLE POTENTIAL FOR THE SYSTEM TO REINTENSIFY THROUGH THE FORECAST PERIOD THOUGH IT IS UNLIKELY TO REACH ITS FORMER PEAK INTENSITY. MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH TAU 36 AS THE SYSTEM HITS ITS SOUTHERN MOST POINT. AFTER TAU 36 UKMET ENSEMBLE AND NAVGEM TAKE THE SYSTEM WESTWARD OVER TAIWAN WHILE THE BULK OF THE GUIDANCE FOLLOWS THE JTWC FORECAST TRACK AND MAKES A TURN GENERALLY NORTHWARD. FOR THIS REASON THE CURRENT TRACK FORECAST IS PLACED WITH HIGH CONFIDENCE WHILE THE EXTENDED TRACK FORECAST IS PLACED WITH MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE SHOWS A GOOD CONSENSUS THAT 12W IS ON A DOWNWARD INTENSITY TRAJECTORY, THE BULK OF THE GUIDANCE SHOWS A STEADY WEAKENING TREND THROUGH TAU 72 AFTER WHICH ALL MEMBERS EXCEPT DECAY-SHIPS (NAVGEM) SHOW A REINTENSIFICATION TREND. FOR THIS REASON THE JTWC INTENSITY FORECAST IS PLACED WITH MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN