WDPN31 PGTW 301500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 12W (HINNAMNOR) WARNING NR 010// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 26.5N 133.6E INITIAL INTENSITY: 130 KTS GEOGRAPHIC REFERENCE: 311 NM EAST OF KADENA AB MOVEMENT PAST 6 HOURS: WESTWARD AT 16 KTS SIGNIFICANT WAVE HEIGHT: 45 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A HIGHLY SYMMETRIC SYSTEM OF TIGHTLY WRAPPING SPIRAL BANDS WITH A 9NM PINHOLE EYE. A 300859Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS THAT A SECOND BANDING FEATURE IS FORMING ON THE WESTERN SIDE OF THE CIRCULATION WHILE THE PRIMARY BANDING FEATURE REMAINS ON THE EASTERN SIDE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON EIR AND SSMIS IMAGERY. THE INITIAL INTENSITY OF 130 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON DVORAK INTENSITY ESTIMATES AND CIMMS INTENSITY ESTIMATES INDICATING 127-140 KNOTS, WITH ALL MEMBERS SHOWING AN UPWARD TREND SINCE THE LAST FORECAST CYCLE. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: DEEP-LAYERED EXTENSION OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T7.0 - 140 KTS RJTD: T7.0 - 140 KTS KNES: T6.5 - 127 KTS CIMSS SATCON: 133 KTS AT 300900Z CIMSS ADT: 127 KTS AT 301140Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE EQUATORWARD 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 FORECAST TO CONTINUE TRACKING GENERALLY WESTWARD THROUGH TAU 12 UNDER THE STEERING INFLUENCE OF THE STR TO THE NORTHEAST. STILL IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY WARM SEA SURFACE TEMPERATURES (30-31C), LOW VERTICAL WIND SHEAR (10-15KTS) AND MODERATE OUTFLOW ALOFT, 12W IS FORECAST TO REACH A POTENTIAL PEAK INTENSITY OF 135KTS OR POSSIBLY HIGHER BY TAU 24. BY THIS TIME, TWO MAIN FACTORS BEGIN TO ALTER THE TRAJECTORY OF 12W. A MIDLATITUDE SHORTWAVE TROUGH IS EXPECTED TO DIG OVER THE KOREAN PENINSULA AND BREAK DOWN THE CURRENT STR TO THE NORTH. AS A RESULT, THE STR TO THE WEST WILL TAKE PRIMARY STEERING CONTROL AND 12W IS FORECAST TO TRACK MORE EQUATORWARD ALONG ITS SOUTHWESTERN PERIPHERY UNTIL ENDING UP IN A COMPETING STEERING SYNOPTIC PATTERN, WITH A STR TO THE NORTHEAST AND WEST, AND A NEAR- EQUATORIAL RIDGE TO THE SOUTH. THE SECOND FACTOR BEING A POTENTIAL BINARY INTERACTION WITH 98W WHICH IS CONSOLIDATING 400NM TO THE SOUTH OF 12W, ALREADY WITHIN CAPTURE DISTANCE. AS THESE FACTORS DEVELOP PAST TAU 24, THE SYSTEM IS FORECAST TO BEGIN TO TRACK SOUTHWESTWARD AND NEAR TAU 48 AS THE STEERING ENVIRONMENT BECOMES INCREASINGLY COMPLICATED TRACK SPEEDS WILL SLOW AND UPWELLING WILL BEING TO SIGNIFICANTLY IMPACT INTENSITY. BY TAU 72 A SIGNIFICANT INFLECTION POINT IS REACHED, MODELS AGREE 12W WILL EXECUTE A POLEWARD TURN WITH A BULK OF THE GUIDANCE INDICATING A GENERALLY NORTHWARD TRACK THROUGH THE FORECAST PERIOD. AFTER THIS TURN BETWEEN TAU 48 AND TAU 72 THERE IS A POTENTIAL FOR REINTENSIFICATION THOUGH THE AMOUNT OF TIME SPENT QS OVER COOLER WATERS WILL HAVE A STRONG IMPACT ON THE LONG-RANGE INTENSITY FORECAST. MODEL DISCUSSION: NUMERICAL MODELS REMAIN IN EXCELLENT AGREEMENT THROUGH TAU 36 AND GOOD AGREEMENT THOUGH TAU 72. AS PREVIOUSLY MENTIONED, WITH THE EXCEPTION OF NAVGEM ALL MEMBERS INDICATE SOME DEGREE OF POLEWARD TURN NEAR TAU 60 WITH THE BULK OF THE GUIDANCE TRENDING GENERALLY NORTHWARD THROUGH THE FORECAST PERIOD WHILE NAVGEM PLOTS A COURSE STRAIGHT INTO THE RIDGE TO THE WEST. FOR THIS REASON THE INITIAL TRACK FORECAST IS PLACED WITH HIGH CONFIDENCE, WHILE THE EXTENDED TRACK FORECAST IS PLACED WITH LOW CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE HAS IMPROVED ITS CONSENSUS SINCE THE PREVIOUS FORECAST THOUGH SOME DISAGREEMENT STILL EXISTS. HWRF AND DECAY-SHIPS (NAVGEM VERSION) REMAIN CONSERVATIVE IN THE NEAR TERM INDICATING SLIGHT WEAKENING WHILE THE REMAINING GUIDANCE SHOWS VARYING AMOUNTS OF INTENSIFICATION THROUGH TAU 24 AFTER WHICH ALL MEMBERS TREND DOWNWARD. AS WE PROGRESS TOWARDS THE AFOREMENTIONED INFLECTION POINT NEAR TAU 60, MODEL OUTPUT IS INCREASINGLY INDICATING REINTENSIFICATION AS THE SYSTEM TRACKS NORTHWARD WITHIN THE NEWLY CREATED COL REGION. FOR THESE REASONS THE INITIAL INTENSITY FORECAST IS PLACED WITH MEDIUM CONFIDENCE WHILE THE EXTENDED INTENSITY FORECAST IS PLACED WITH LOW CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: LOW// NNNN