WDPN31 PGTW 050900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (DOLPHIN) WARNING NR 038// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 25.6N 137.2E INITIAL INTENSITY: 95 KTS GEOGRAPHIC REFERENCE: 509 NM EAST OF KADENA AB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 45 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICT TYPHOON (TY) 12W WITH A CLOUD-FILLED, BUT WELL-DEFINED 17NM WIDE EYE EMBEDDED WITHIN A SYMMETRIC CENTRAL DENSE OVERCAST (CDO). EYE TEMPERATURES CONTINUE TO COOL, NOW ESTIMATED AT -04C AS THE EYE FILLS WITH CLOUDS, WHILE CLOUD-TOP TEMPERATURES HAVE STEADILY RISEN TO THE -45C RANGE, CONSISTENT WITH CLOUD-TOP TEMPS FROM 12 HOURS AGO. A 050436Z AMSR2 AND 050659Z SSMIS 89GHZ IMAGE DEPICT A COMPACT INNER CORE OF CONVECTION, SURROUNDED BY AN EXPANSIVE OUTER RING OF MODERATE CONVECTION. THE SSMIS IMAGE DEPICTS A STATIONARY BANDING COMPLEX (SBC), WHICH THE CIMSS M-PERC FAILS TO PICK UP, DRAPED ACROSS THE SOUTHERN REGION OF THE CIRCULATION AND WRAPS UP ALONG THE EASTERN SIDE, ULTIMATELY MERGING WITH THE INNER EYEWALL IN THE NORTHEASTERN QUADRANT. BOTH MICROWAVE IMAGES ALSO DEPICT A RELATIVELY CLEAR MOAT SEPARATING THE SBC FROM THE MAIN CORE OF CONVECTION AND INNER EYEWALL. THE FACT THAT M-PERC IS NOT PICKING UP ON THIS SBC IS NOTABLE FOR FUTURE EYEWALL REPLACEMENT CYCLE PREDICTION. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE EYE IN THE MSI. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A BLEND OF THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES NOTED BELOW. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE, WITH WARM SSTS (ALTHOUGH OHC REMAINS LOW), STRONG RADIAL OUTFLOW (DIVERGENT CYCLONIC IN THE IMMEDIATE VICINITY OF THE CORE, TURNING ANTICYCLONIC AT A DISTANCE) AND LOW DEEP-LAYER SHEAR. INITIAL WIND RADII BASIS: SCATTEROMETER AND SAR DATA AS WELL AS PERSISTENCE. CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED OVER THE SEA OF JAPAN. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.0 - 90 KTS RJTD: T6.0 - 115 KTS RCTP: T5.0 - 90 KTS KNES: T4.5 - 77 KTS CIMSS SATCON: 94 KTS AT 050630Z CIMSS ADT: 97 KTS AT 050600Z CIMSS AIDT: 99 KTS AT 050600Z CIMSS D-MINT: 102 KTS AT 050659Z CIMSS D-PRINT: 89 KTS AT 050630Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL 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 IS FORECAST TO CONTINUE ITS WESTWARD TRACK TOWARDS THE RYUKYU ISLANDS UNDER THE STEERING INFLUENCE OF THE STRONG STR CENTERED OVER THE SEA OF JAPAN. TRACK SPEEDS ARE FORECAST TO REMAIN CONSISTENT FOR THE NEXT 36-48 HOURS AS THE RIDGE REMAINS FIRMLY ENTRENCHED TO THE NORTH. SOME TROCHOIDAL WOBBLES ARE ANTICIPATED, ESPECIALLY IF AND WHEN THE SYSTEM BEGINS ANOTHER ERC, THOUGH THERE ARE NO SIGNIFICANT CHANGES IN TRACK EXPECTED BEFORE THE SYSTEM REACHES THE RYUKYUS. BY TAU 48, AN UPPER-LEVEL TROUGH WILL MOVE ACROSS FAR NORTHEASTERN CHINA, ERODING THE WESTERN EXTENT OF THE STR, INDUCING A BREAK OR WEAKNESS IN THE STEERING RIDGE OVER THE KOREAN PENINSULA. THE TROUGH IS NOT FORECAST TO BE STRONG ENOUGH TO PULL TY 12W NORTHWARD, THOUGH ITS PRESENCE INTRODUCES SOME MARGINAL UNCERTAINTY INTO THE FORECAST TRACK. ALL OF THE MAJOR GLOBAL MODELS DEPICT THE SAME SCENARIO, WITH A WEAKNESS DEVELOPING IN THE RIDGE OVER THE KOREAN PENINSULA, BUT DIFFERENCES EMERGE IN HOW THE MODELS PREDICT TY 12W TO RESPOND. THE NAVGEM, WITH ITS KNOWN POLEWARD TRACK BIASES SHOW AN AGGRESSIVE RESPONSE AND A DRAMATIC TURN NORTHWARD, THOUGH NOW DELAYED SIGNIFICANTLY LATER THAN IN PREVIOUS RUNS. THE GFS STILL INSISTS ON TURNING THE SYSTEM POLEWARD BUT A SHALLOWER ANGLE AND NOT UNTIL AFTER PASSING OKINAWA. ENSEMBLES WILL BE DISCUSSED IN MORE DETAIL BELOW BUT IN GENERAL SUPPORT A WESTWARD TRAJECTORY THROUGH TAU 120, WITH A LOW PROBABILITY SCENARIO OF A TURN NORTHWARD AFTER TAU 96. THE SYSTEM IS EXPECTED TO SLOW DOWN AFTER TAU 48, BUT MAINTAIN A GENERALLY WESTWARD TRACK THROUGH TAU 120. THE FIRST LANDFALL IS FORECAST TO OCCUR AT OKINAWA AROUND TAU 48, WITH A SECOND LANDFALL SOUTH OF SHANGHAI BETWEEN TAU 96 AND TAU 120. REGARDING INTENSITY, WHILE THE SOLE ERC PREDICTION AID IS CURRENTLY NOT PICKING UP ON A STRONG SBC SIGNATURE, THE PRESENCE OF CYCLONIC OUTFLOW ALOFT AND THE PRESENCE OF THE SBC STRONGLY SUGGEST SECONDARY EYEWALL FORMATION IS LIKELY. IF THE SYSTEM ATTEMPTS ANOTHER ERC, DUE TO THE EXTREMELY BROAD NATURE OF THE OUTER CONVECTIVE RING, AND OCEANIC UPWELLING, IT IS UNLIKELY TO BE ABLE TO COMPLETE IT. THE FORECAST CALLS FOR A STEADY INTENSITY, WITH THE POSSIBILITY OF SWINGS OF PLUS OR MINUS 5-10 KNOTS, OVER THE NEXT 48 HOURS AS THE SYSTEM HURTLES TOWARDS OKINAWA. AFTER MOVING INTO THE ECS, THE SYSTEM WILL RAPIDLY WEAKEN AS IT CONTINUES TO EXPAND, UPWELLS SIGNIFICANTLY COOLER WATERS AND ENCOUNTERS SOME CONVERGENCE ALOFT. AFTER LANDFALL IN CHINA, THE SYSTEM WILL RAPIDLY WEAKEN DUE TO LAND EFFECTS. MODEL DISCUSSION: TRACK GUIDANCE IS BY AND LARGE CONTINUING TO TREND TOWARDS STRONGER AGREEMENT. GFS AND GEFS ARE NOW THE SOLE OUTLIERS, TRANSITIONING THE SYSTEM NORTHWESTWARD AFTER TAU 72, WITH THE JGSM NOW HAVING GIVEN UP ON THE POLEWARD TURN AND NOW ALIGNING WITH THE BULK OF THE OTHER MODELS. THE NAVGEM DIVES THE SYSTEM SOUTHWESTWARD, PASSING OVER THE SOUTHERN TIP OF OKINAWA, THEN MAKES A LITERAL RIGHT TURN AT TAU 96. THE REMAINDER OF THE GUIDANCE PACKAGE IS CONFINED TO A ENVELOPE WHICH GRADUALLY EXPANDS TO 230NM AT TAU 120, WITH EC-AIFS, JGSM AND THE UKMET ENSEMBLE ON THE NORTHERN EDGE AND THE GALWEM ON THE SOUTHERN. ENSEMBLE GUIDANCE IS ALSO COMING INTO BETTER AGREEMENT. OF THE AVAILABLE, RELIABLE ENSEMBLE MODELS (GEFS, EPS, ICON, AIFS, GDM), ONLY THE GEFS SHOWS A SIGNIFICANT NUMBER OF MEMBERS TURNING POLEWARD, WITH APPROXIMATELY 50 PERCENT DOING SO AFTER TAU 84 AND ALL BUT TWO REMAIN WEST OF 128E. EVERY OTHER ENSEMBLE NOTED ABOVE DEPICTS A WEST-NORTHWESTWARD TRACK THROUGH LANDFALL IN CHINA, WITH MEMBERS CONFINED TO AN ENVELOPE BETWEEN SHANGHAI AND NORTHERN TAIWAN. THE JTWC FORECAST IS PLACED NEAR THE AI CONSENSUS MEAN WITH HIGH CONFIDENCE. INTENSITY GUIDANCE IS IN RELATIVELY GOOD AGREEMENT, THE BULK OF MODELS DEPICTING A TIGHTLY CONFINED ENVELOPE PLUS OR MINUS 10 KNOTS OF 95 KNOTS THROUGH TAU 48, THEN QUICKLY WEAKENING THEREAFTER. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH TRACK 72-120 HR: HIGH INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN