WDPN31 PGTW 120900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 04W (SINLAKU) WARNING NR 014// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 10.3N 150.6E INITIAL INTENSITY: 130 KTS GEOGRAPHIC REFERENCE: 398 NM EAST-SOUTHEAST OF NAVSTA GUAM MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS SIGNIFICANT WAVE HEIGHT: 36 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: A COMPREHENSIVE DIAGNOSIS OF THE SYNOPTIC ENVIRONMENT REVEALS AN EXCEPTIONALLY CONDUCIVE REGIME FOR INTENSIFICATION, CHARACTERIZED BY LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), A DEEPLY MOIST TROPOSPHERIC COLUMN, AND WARM (28-29 C) SEA SURFACE TEMPERATURES (SST). FURTHERMORE, A ROBUST, EFFICIENT RADIAL OUTFLOW STRUCTURE IS BEING AUGMENTED BY AN UPPER-LEVEL TROUGH, WITH THE AXIS CENTERED TO THE NORTHEAST AND A NEAR-EQUATORIAL RIDGE TO THE SOUTHEAST. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS THE MORPHOLOGICAL RESPONSE TO THESE CONDITIONS, WITH SUPER TYPHOON (STY) 04W (SINLAKU) ACHIEVING A NEAR-PERFECT SYMMETRY OF THE CENTRAL EYE FEATURE. SURROUNDING THE 20 NM DIAMETER EYE, SIMILARLY A COHESIVE CENTRAL DENSE OVERCAST (CDO) IS OBSERVED. CONTINUOUS RAPID INTENSIFICATION (RI) IS THEREFORE WITNESSED BY ADDING THE EYE TEMPERATURE INCREASING TO 16 C TO THE OVERALL ASSESSMENT. THE INITIAL POSITION IS PINPOINTED WITH HIGH FIDELITY BASED ON THE VISIBLE IMAGERY LOOP. THE INITIAL INTENSITY IS ESTIMATED WITH MEDIUM CONFIDENCE AT 130 KTS, CONSIDERING THE AGENCIES DVORAK INTENSITY ASSESSMENT ENVELOPE OF T6.0-T7.5, AND OBJECTIVE ESTIMATES RANGING FROM 127 TO 143 KTS. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: WEAK STEERING ENVIRONMENT WITH A NEAR-EQUATORIAL RIDGE (NER) TO THE SOUTHEAST AND A SUBTROPICAL RIDGE (STR) TO THE NORTHWEST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T6.5 - 127 KTS RJTD: T6.0 - 115 KTS RCTP: T7.5 - 155 KTS KNES: T7.0 - 140 KTS CIMSS SATCON: 128 KTS AT 120311Z CIMSS ADT: 127 KTS AT 120530Z CIMSS AIDT: 133 KTS AT 120530Z CIMSS D-MINT: 128 KTS AT 120536Z CIMSS D-PRINT: 143 KTS AT 120530Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 5-10 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG RADIAL OTHER FACTORS: OUTFLOW IS FURTHER ENHANCED BY THE DEEP-LAYER TROUGH TO THE NORTHEAST 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: THE PERSISTENCE OF A HIGHLY FAVORABLE ATMOSPHERIC AND OCEANIC REGIME IS EXPECTED TO FUEL ANOTHER BRIEF PERIOD OF RAPID INTENSIFICATION, WITH A PROJECTED PEAK INTENSITY OF 140-145 KTS WITHIN THE NEXT 24 HOURS. THIS INTENSE PHASE WILL OCCUR AS STY 04W ACCELERATES ON A GENERALLY NORTHWESTWARD TRAJECTORY, A MOTION DRIVEN BY THE ANTICIPATED DEVELOPMENT OF A NORTHWARD EXTENSION OF THE NEAR-EQUATORIAL RIDGE, WHICH IS EXPECTED TO EVENTUALLY BECOME THE PRIMARY STEERING MECHANISM. DUE TO THE EXPANSIVE NATURE OF THE WIND FIELD, GALE-FORCE WINDS ARE EXPECTED TO IMPACT THE MARIANA ISLANDS SHORTLY AFTER TAU 24. WHILE THE SYSTEM IS CURRENTLY FORECAST TO REACH ITS PEAK INTENSITY PRIOR TO TAU 24, THE WEAKENING TREND AFTERWARDS IS PREDICTED TO BE GRADUAL, AS THE MAJORITY OF THE ENVIRONMENTAL PARAMETERS WILL REMAIN HIGHLY FAVORABLE. GLOBAL MODEL GUIDANCE INDICATES THAT THE INCREASED DISTANCE FROM THE UPPER-LEVEL TROUGH TO THE NORTHEAST PROVIDING THE SUPERCHARGED OUTFLOW AVENUE AT THE MOMENT WILL RESULT IN SLIGHTLY DECREASED LEVELS OF 200 MB DIVERGENCE. AROUND TAU 72, THE SYSTEM WILL BEGIN ITS RECURVATURE AROUND THE SOUTHWESTERN PERIPHERY OF THE BUILDING RIDGE TO THE EAST AND WILL ENCOUNTER A MODEST INCREASE IN VERTICAL WIND SHEAR, AS WELL AS DRY AIR ENTRAINMENT, CONTRIBUTING TO A STEADIER WEAKENING. MODEL DISCUSSION: CONFIDENCE IN THE TRACK FORECAST IS IMPROVING OWING TO A NOTABLE INCREASE IN AGREEMENT AMONG DYNAMICAL MODELS REGARDING THE EVOLUTION OF THE DEEP-LAYER STEERING PATTERN. WHILE THE PREVIOUS CONCERN REGARDING A COMPETING STEERING ENVIRONMENT STILL EXISTS, MODELS CONTINUE TO CONVERGE ON A SCENARIO WHERE THE NORTHWARD-BUILDING NEAR-EQUATORIAL RIDGE BECOMES THE PRIMARY STEERING MECHANISM, FAVORING A CONSISTENT RECURVATURE. LONG-TERM TRACK FORECAST CONFIDENCE IS HOWEVER, STILL ASSESSED AS LOW DUE TO A 250 NM CROSS-TRACK SPREAD AROUND TAU 96, INDICATING UNCERTAINTY ASSOCIATED WITH THE TIMELINE OF STY 04W, ROUNDING THE AXIS OF THE RIDGE. SLIGHTLY INCREASED CERTAINTY IS REFLECTED IN THE NEAR-TERM TRACK GUIDANCE, WHICH SHOWS A CROSS-TRACK SPREAD OF LESS THAN 80 NM AMONG CONSENSUS MEMBERS AROUND THE TIME OF CPA TO TINIAN, AND MOST SOLUTIONS CLUSTERED BETWEEN ROTA AND SAIPAN. NAVGEM REMAINS THE PRIMARY OUTLIER STILL OFFERING TRACK SOUTHWEST OF ROTA. THE CONSENSUS GUIDANCE TRACK SPREAD WITHOUT NAVGEM IS ESTIMATED AT 52 NM AROUND TAU 48. WITH REGARD TO INTENSITY, THE OFFICIAL FORECAST IS ALIGNED CLOSELY WITH THE HAFS SOLUTION AND IS SET SLIGHTLY ABOVE THE MULTI-MODEL MEAN WITH MEDIUM CONFIDENCE, PROJECTING A 140-145 KTS PEAK PRIOR TO TAU 24. THIS IS MORE AGGRESSIVE THAN THE GLOBAL DETERMINISTIC AND STATISTICAL-DYNAMICAL MODELS, BUT IS SUPPORTED BY A FEW REMAINING RAPID INTENSIFICATION INDICES, AS WELL AS HAFS. OF NOTE, THE RI SIGNAL HAS DECREASED SINCE THE PREVIOUS WARNING, INDICATING THAT THE PEAK IS LIKELY TO OCCUR WITHIN THE NEXT FEW HOURS. FORECAST CONFIDENCE: TRACK 00-72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN