WDPN31 PGTW 142100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 04W (SINLAKU) WARNING NR 024// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.2N 145.4E INITIAL INTENSITY: 115 KTS GEOGRAPHIC REFERENCE: 23 NM WEST OF SAIPAN MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS SIGNIFICANT WAVE HEIGHT: 40 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A DEGRADING INNER EYEWALL WITH ASSOCIATED EXPANSION OF THE EYE (NOW 30 NM DIAMETER) AS THE ERC APPROACHES COMPLETION. A 141603Z AMSR2 89 GHZ MICROWAVE IMAGE SHOWS THAT THE INNER EYEWALL HAS SHALLOWED CONSIDERABLY AND THE OUTER EYEWALL HAS RETAINED ITS SYMMETRIC CIRCULAR STRUCTURE. CLOUD TOPS HAVE CONTINUED TO WARM, PARTICULARLY IN THE NORTHWEST QUADRANT, SUGGESTING CONTINUED WEAKENING. CIRRUS FILAMENTS AND TRANSVERSE BANDING EXPANDING RADIALLY OUTWARD IN ANIMATED WATER VAPOR IMAGERY INDICATE MODERATE RADIAL OUTFLOW. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE LOCATION IN ANIMATED EIR. THE INITIAL INTENSITY OF 115 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON AGENCY DVORAK FIXES AND CIMSS OBJECTIVE ESTIMATES LISTED BELOW. THE ENVIRONMENT REMAINS FAVORABLE WITH WARM SEA SURFACE TEMPERATURES (SST), LOW VERTICAL WIND SHEAR (VWS), AND GOOD OUTFLOW ALOFT. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: NORTHWARD EXTENSION OF THE NEAR-EQUATORIAL RIDGE TO THE EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T6.0 - 115 KTS RJTD: T7.0 - 140 KTS RCTP: T7.0 - 140 KTS KNES: T6.0 - 115 KTS CIMSS SATCON: 129 KTS AT 141800Z CIMSS ADT: 119 KTS AT 141800Z CIMSS AIDT: 112 KTS AT 141800Z CIMSS D-PRINT: 115 KTS AT 141800Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 0-5 KTS SST: 28-29 CELSIUS OUTFLOW: MODERATE RADIAL OTHER FACTORS: ONGOING EYEWALL REPLACEMENT CYCLE (ERC) ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM 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 (TY) 04W (SINLAKU) IS FORECAST TO BEGIN TURNING TOWARD A NORTH-NORTHWESTWARD TRACK IN THE NEXT 12 HOURS AS IT APPROACHES THE AXIS OF THE NER EXTENSION EAST. THE SYSTEM WILL HAVE ROUNDED THE RIDGE AXIS AND TURNED NORTH-NORTHEASTWARD BY TAU 48 AS THE EASTERN RIDGE EXTENSION BUILDS AND MIGRATES WESTWARD, EVENTUALLY ANCHORING TO THE SOUTH OF 04W. AFTER TAU 48, SINLAKU IS FORECAST TO ACCELERATE NORTHEASTWARD THROUGH THE END OF THE FORECAST PERIOD, CURVING TO AN EAST-NORTHEASTWARD TRACK AS IT BECOMES EMBEDDED IN THE MIDLATITUDE WESTERLIES. AS A RESULT, 04W IS EXPECTED TO BEGIN EXTRATROPICAL TRANSITION NEAR TAU 120 AND RAPIDLY COMPLETE THE TRANSITION THEREAFTER. THE INTENSITY IS FORECAST TO CONTINUE A GRADUAL WEAKENING TREND THROUGH TAU 48 DUE TO THE INTERNAL DYNAMICS OF THE SOON-TO-BE COMPLETED ERC PROCESS. AFTER TAU 48, SINLAKU IS FORECAST TO CONTINUE WEAKENING AS IT MOVES OVER COOLER SSTS (25-26 C BECOMING 20-21C BY TAU 120) AND WESTERLY VWS INCREASES FROM TO 45-50 KTS AT TAU 120 WITHIN THE WESTERLIES. MODEL DISCUSSION: EXCLUDING NAVGEM AS A SIGNIFICANT OUTLIER TO THE WEST, MODEL TRACK GUIDANCE IS IN GOOD AGREEMENT ABOUT THE RECURVING SCENARIO, WITH A CROSS-TRACK SPREAD OF 170 NM AT TAU 72 AND 210 AT TAU 120. THIS IS A MARKED IMPROVEMENT OVER PREVIOUS MODEL RUNS. THE JTWC TRACK FORECAST IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE THROUGH TAU 72 AND MEDIUM CONFIDENCE THEREAFTER. MODEL INTENSITY GUIDANCE AGREES ON THE WEAKENING TREND THROUGHOUT THE FORECAST PERIOD. COAMPS-TC IS AN OUTLIER WITH A MUCH FASTER RATE OF WEAKENING THAN THE REMAINDER OF GUIDANCE, WHICH REMAINS CLOSE TO THE CONSENSUS. THE JTWC INTENSITY FORECAST IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH OVERALL MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN