WDPN31 PGTW 051500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (DOLPHIN) WARNING NR 039// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 25.9N 136.2E INITIAL INTENSITY: 90 KTS GEOGRAPHIC REFERENCE: 454 NM EAST OF KADENA AB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 41 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A VERY COMPACT INNER CORE OF MODERATE CONVECTION SURROUNDING A SMALL, APPROXIMATELY 10NM WIDE EYE FEATURE, WHICH WAS SEVERELY ERODED ON THE WESTERN FLANK. ANIMATED SHORTWAVE INFRARED AND PROXY VISIBLE IMAGERY AND A 051114Z MHS 89GHZ MICROWAVE IMAGE DEPICT A STATIONARY BANDING FEATURE (SBC) WRAPPING IN FROM THE SOUTH, UP THE EASTERN FLANK AND INTO THE INNER CORE IN THE NORTHEASTERN QUADRANT, AS WELL AS A MOAT OF RELATIVELY DRIER AIR EXTENDING AROUND NEARLY THE ENTIRE EXTENT OF THE INNER CORE. LATER EIR IMAGERY DEPICTS THE EYEWALL REFORMING ALONG THE WESTERN FLANK OF THE SYSTEM, THOUGH THE EYE CONTINUES TO SHRINK IN SIZE. ANIMATED WATER VAPOR IMAGERY, AND DERIVED ATMOSPHERIC MOTION VECTORS CONTINUE TO SHOW CYCLONIC OUTFLOW ALOFT, WHICH TURNS ANTICYCLONIC ROUGHLY 100NM OUT FROM THE CENTER, AND NO DISTINCT OUTFLOW CHANNELS. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE SMALL EYE IN THE EIR. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A BLEND OF THE AVAILABLE OBJECTIVE AND SUBJECTIVE INTENSITY ESTIMATES NOTED BELOW. LATE RECEIPT OF A TRIFECTA OF SAR PASSES FROM APPROXIMATELY 0900Z (S1C, RCM3 AND RSAT2) BRINGS THE INTENSITY ASSESSMENT INTO QUESTION, AS ALL THREE SHOWED A VMAX SIGNIFICANTLY LOWER THAN THE CURRENT INTENSITY ESTIMATES. THOUGH RECEIVED TOO LATE TO INFLUENCE THIS FORECAST, LATER REANALYSIS MAY RESULT IN A LOWER INITIAL INTENSITY. ENVIRONMENTAL CONDITIONS REMAIN GENERALLY FAVORABLE. SSTS REMAIN VERY WARM, THOUGH OHC IS LOW AS THE WARM LAYER IS VERY THIN. OHC INCREASES TO THE WEST REACHING A LOCAL MAXIMUM JUST EAST OF OKINAWA. UPPER-LEVEL OUTFLOW IS MODERATE TO STRONG, BUT THE CYCLONIC NATURE OF THE UPPER-LEVEL FLOW PRODUCES AN OVERALL NEGATIVE EFFECT ON TC INTENSITY. SHEAR REMAINS LOW, WITH NO MAJOR CHANGES EXPECTED. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: SOUTHERN FLANK OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED OVER THE SEA OF JAPAN (SOJ). AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.0 - 90 KTS RJTD: T5.5 - 102 KTS RCTP: T4.5 - 77 KTS KNES: T4.5 - 77 KTS CIMSS ADT: 95 KTS AT 051200Z CIMSS AIDT: 94 KTS AT 051200Z CIMSS D-PRINT: 88 KTS AT 051130Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL OTHER FACTORS: SECONDARY EYEWALL FORMATION. ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY 12W HAS TAKEN A BIT OF A MORE WEST-NORTHWESTWARD TRACK THAN EXPECTED OVER THE PAST 12 HOURS, SOME OF WHICH CAN BE ATTRIBUTED TO TROCHOIDAL WOBBLE, BUT ALSO DUE TO A SLIGHT DISPLACEMENT OF THE STR FURTHER NORTH THAN ANTICIPATED. OVER THE PAST TWO HOURS, HOWEVER, THE TRACK APPEARS TO BE STABILIZING, MOVING DUE WESTWARD ALONG THE 26N LATITUDE LINE. THE SYSTEM IS EXPECTED TO CONTINUE TRACKING WEST-NORTHWESTWARD ALONG THE SOUTHERN SIDE OF THE STR OVER THE SOJ THROUGH THE ENTIRE FORECAST PERIOD. GLOBAL MODELS STILL SHOW A MAJOR SHORTWAVE TROUGH MOVING ACROSS NORTHEASTERN CHINA AND INTO EASTERN RUSSIA BY TAU 48, AND THEY STILL SHOW A WEAKNESS DEVELOPING IN THE DEEP-LAYER STEERING RIDGE OVER THE KOREAN PENINSULA. HOWEVER, THE GLOBAL MODELS ALSO DEPICT THE TROUGH WEAKENING AND RECEDING NORTHWARD RELATIVELY QUICKLY, REPLACED BY DEEP-LAYER RIDGING EXTENDING POLEWARD OVER SOUTHERN JAPAN AND INTO THE KOREAN PENINSULA BY TAU 96. THUS, THE MODELS HAVE BEGUN TO AGREE THAT THE IMPACT ON TY 12W WILL BE LIMITED TO A SLOWDOWN IN TRACK SPEED AFTER TAU 48, WITH LITTLE IMPACT ON THE OVERALL TRAJECTORY OF THE SYSTEM. ENSEMBLES, WHICH WILL BE DISCUSSED IN MORE DETAIL BELOW, ARE ALSO SHOWING DECREASED UNCERTAINTY AND MEMBER SPREAD, WITH FEWER MEMBERS DEPICTING A POLEWARD TURN, PROVIDING INCREASED CONFIDENCE TO THE JTWC FORECAST TRACK. LANDFALL ON OKINAWA IS FORECAST TO OCCUR BETWEEN TAU 36 AND TAU 48, AND A SECOND LANDFALL IS EXPECTED IN CENTRAL ZHEJIANG PROVINCE, CHINA, SHORTLY AFTER TAU 96. OF NOTE, RECENT SAR AND SCATTEROMETER DATA REVEALS AN ASYMMETRIC WIND FIELD, WITH A MOAT OF RELATIVELY WEAKER, GALE-FORCE, WINDS EMBEDDED WITHIN THE SOUTHWESTERN QUADRANT OF THE CIRCULATION BETWEEN BANDS OF HIGHER STORM-FORCE WINDS. THIS SAME SETUP HAS PERSISTED FOR THE PAST TWO DAYS, AND LIKELY WILL PERSIST FOR THE NEXT TWO DAYS AS THE SYSTEM APPROACHES OKINAWA. REGARDING INTENSITY, THE SYSTEM CONTINUES TO WEAKEN AND AS NOTED ABOVE, MAY BE WEAKER THAN CURRENTLY ESTIMATED. HOWEVER, RELIABLE INTENSITY GUIDANCE SUGGESTS THE SYSTEM WILL CONTINUE TO MAINTAIN AN 80-85 KNOT INTENSITY THROUGH AT LEAST TAU 48 BEFORE IT BEGINS TO RAPIDLY WEAKEN IN THE EAST CHINA SEA DUE TO INCREASED SHEAR, AND OCEANIC UPWELLING BEFORE BEGINNING TO DISSIPATE OVER SOUTHEASTERN CHINA AFTER LANDFALL. MODEL DISCUSSION: TRACK GUIDANCE IS IN GOOD AGREEMENT AND CONTINUES THE TREND SEEN EARLIER IN THAT THE MODELS ARE COMING INTO BETTER AGREEMENT ON THE WEST-NORTHWESTWARD TRACK SCENARIO, WITH A COUPLE OF NOTABLE OUTLIERS. THE NAVGEM CONTINUES TO DEVIATE FROM THE CONSENSUS ENVELOPE AND TAKE THE SYSTEM OVER SOUTHERN OKINAWA BEFORE STOPPING AND TURNING SHARPLY POLEWARD AFTER TAU 72 WHEREAFTER IT TRACKS PERPENDICULAR TO THE REMAINDER OF THE GUIDANCE. THE GFS AND GEFS COMBO STILL INSIST ON A NORTHWESTWARD TRACK AFTER TAU 72, BUT CONTINUE TO PUSH THE TRACK FURTHER WEST WITH EAST RUN, NOW SHOWING A TAU 120 POSITION IN THE VICINITY OF SHANGHAI. THE REMAINDER OF THE CONSENSUS PACKAGE IS CONSTRAINED TO AN ENVELOPE THAT GRADUALLY EXPANDS TO 170NM BY TAU 120. GALWEM IS THE SOUTHERN OUTLIER, WITH THE CONSENSUS MEAN (BEING PULLED NORTHWARD BY GFS, GEFS AND NAVGEM) POSITIONED ON THE NORTHERN EDGE OF THE ENVELOPE. ENSEMBLE GUIDANCE INCLUDING GEFS, EPS, ICON, AIFS, AND GDM, CONTINUE TO TREND TOWARDS BETTER AGREEMENT ON A WESTWARD TRACK. THE ONLY MODEL SHOWING MEMBERS TURNING NORTHWARD IS GEFS, WHICH SHOWS ROUGHLY 50 PERCENT OF ITS MEMBERS TURNING NORTHWESTWARD TOWARDS SHANGHAI, AND THREE MEMBERS TURNING NORTHWARD, ALL OF WHICH ARE WEST OF 127E LONGITUDE. THE REMAINDER OF THE MODEL MEMBERS ALL POINT TO A WEST-NORTHWEST TRACK, WITH 99 PERCENT OF THE MEMBERS TRACKING SOUTH OF SHANGHAI. THE JTWC FORECAST IS PLACED NEAR THE AI CONSENSUS MEAN WITH HIGH CONFIDENCE. INTENSITY GUIDANCE IS IN RELATIVELY GOOD AGREEMENT. ONLY THE CTCX MODEL DEPICTS SIGNIFICANT INTENSIFICATION, THOUGH HWRF DOES SHOW THE SYSTEM REINTENSIFYING AFTER TAU 12 TO A PEAK OF 95 KNOTS. THE REMAINDER OF THE CONSENSUS MEMBERS SHOW A FLAT INTENSITY TREND THROUGH TAU 48 FOLLOWED BY RAPID WEAKENING THROUGH THE END OF THE FORECAST. THE JTWC FORECAST IS PLACED NEAR THE CONSENSUS MEAN WITH MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH TRACK 72-120 HR: HIGH INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN