WDPN31 PGTW 060300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 09W (BAVI) WARNING NR 021// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 14.3N 145.0E INITIAL INTENSITY: 150 KTS GEOGRAPHIC REFERENCE: 1211 NM SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 11 KTS SIGNIFICANT WAVE HEIGHT: 54 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: CURRENT SYNOPTIC AND MESOSCALE ENVIRONMENTAL ANALYSIS DEPICTS A CONTINUOUSLY, HIGHLY CONDUCIVE KINEMATIC AND THERMODYNAMIC REGIME. THIS OPTIMIZED ENVIRONMENT IS CHARACTERIZED BY ROBUST OCEANIC HEAT CONTENT COUPLED WITH ELEVATED SEA SURFACE TEMPERATURES (SST) OF 29-30 C, DEEP TROPOSPHERIC MOISTURE AND VIGOROUS UPPER-LEVEL RADIAL DIVERGENCE. DEEP-LAYER VERTICAL WIND SHEAR (VWS) HAS INCREASED JUST SLIGHTLY TO 10-15 KTS OVER THE LAST 6 HOURS. REFLECTING THESE OVERALL HIGHLY FAVORABLE DYNAMICS, ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS SUPER TYPHOON (STY) 09W (BAVI) POSSESSING A HIGHLY SYMMETRICAL 25 NM DIAMETER EYE FEATURE EMBEDDED WITHIN A UNIFORM CENTRAL DENSE OVERCAST (CDO) SHIELD. DEEP CONVECTIVE FEEDER BANDS CONVERGING INTO THE CENTRAL CORE DEPICT EXTREMELY COLD CLOUD TOP TEMPERATURES PLUMMETING TO -81 C CONTRASTED AGAINST THE WARM 17 C EYE SIGNATURE. THE THERMAL DIFFERENTIAL HAS THEREFORE DECREASED FROM 101 C TO 98 C SINCE THE LAST WARNING, INDICATING SOME MINOR WEAKENING IN CONVECTIVE STRENGTH. RELYING ON THE EXCEPTIONALLY CLEAR EYE, THE INITIAL SYNOPTIC POSITION IS ANCHORED WITH HIGH CONFIDENCE. AN INITIAL INTENSITY ESTIMATE OF 150 KTS IS ESTABLISHED WITH MEDIUM CONFIDENCE. THIS IS SYNTHESIZED FROM A STRICT CONSENSUS OF AGENCY SUBJECTIVE DVORAK ASSESSMENTS, WHEREAS OBJECTIVE CIMSS SATELLITE-DERIVED INTENSITY ALGORITHMS REMAIN SLIGHTLY LOWER, HOVERING NEAR 135-145 KTS WITH PREVIOUSLY INDICATED REDUCED CONVECTIVE THERMAL DIFFERENTIAL. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK AND A 052244Z METOP-B ASCAT PASS CURRENT STEERING MECHANISM: EASTERN EXTENSION OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED NEAR OKINAWA AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T7.5 - 155 KTS RJTD: T7.5 - 155 KTS RCTP: T7.5 - 155 KTS KNES: T7.5 - 155 KTS CIMSS SATCON: 144 KTS AT 052200Z CIMSS ADT: 137 KTS AT 060000Z CIMSS AIDT: 135 KTS AT 060000Z CIMSS D-MINT: 148 KTS AT 052051Z CIMSS D-PRINT: 143 KTS AT 060000Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL 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: PRIMARY SYNOPTIC STEERING DYNAMICS REMAIN GOVERNED BY THE MATURING EASTERN EXTENSION OF A NORTHWESTERN STR, WHICH WILL DICTATE THE WEST-NORTHWESTWARD PROPAGATION OF STY 09W. AS THIS STEERING RIDGING CONSOLIDATES, TRANSLATIONAL ACCELERATION WILL COMMENCE, DRIVING THE CYCLONIC VORTEX ON A WEST-NORTHWESTWARD VECTOR THROUGH TAU 72. BEYOND THIS TEMPORAL BENCHMARK, STY 09W IS FORECAST TO MODIFY ITS TRAJECTORY MORE POLEWARD, TRACKING ALONG THE WEST-SOUTHWESTERN PERIPHERY OF THE AFOREMENTIONED STEERING STR. EXTENDED-RANGE GUIDANCE INTRODUCES MINOR SPATIAL BIFURCATION, PRESENTING UNCERTAINTY BETWEEN A SHARPER RECURVATURE AROUND THE RIDGE AXIS VERSUS A SHALLOWER TRAJECTORY DIRECTED TOWARD NORTHERN TAIWAN, WITH THE LATTER SCENARIO CURRENTLY HOLDING HEAVY PREFERENCE AMONG PREDICTIVE MODELS. THERMODYNAMICALLY, THE TROPICAL CYCLONE IS PROJECTED TO UNDERGO A BRIEF PHASE OF MODEST DEGRADATION CATALYZED BY A TEMPORARY RESTRICTION IN UPPER-LEVEL OUTFLOW POTENTIAL AND MINOR INCREASE IN VWS. ADDITIONALLY, RECENT 052049Z F17 SSMIS MICROWAVE SUITE DEPICTS A FORMING SECONDARY EYEWALL, WHICH COMBINED WITH HIGH MPERC EYEWALL REPLACEMENT CYCLE (ERC) PREDICTIONS FROM CIMSS BRING ADDITIONAL UNCERTAINTY TO THE INTENSITY ASSESSMENT. HOWEVER, A BRIEF RESUMPTION OF DEEPENING IS ANTICIPATED AROUND TAU 36, AS A HIGHLY EFFICIENT, AUXILIARY WESTWARD DIVERGENT OUTFLOW CHANNEL DEVELOPS. SUBSEQUENT TO THIS SECONDARY KINEMATIC PEAK, AN ESCALATION IN DEEP-LAYER VWS ALONGSIDE CONCURRENT OUTFLOW REDUCTION WILL ARREST FURTHER DEVELOPMENT AND INDUCE A GRADUAL YET STEADY WEAKENING PHASE. DESPITE THIS TERMINAL DECAY, THE SYSTEM WILL SUSTAIN FORMIDABLE TYPHOON CHARACTERISTICS FEATURING A MASSIVELY EXPANDED WIND RADII ENVELOPE. MODEL DISCUSSION: DETERMINISTIC NUMERICAL WEATHER PREDICTION TRACK GUIDANCE MAINTAINS GOOD COHESION THROUGH TAU 72. THIS IS EVIDENCED BY A CROSS-TRACK SPREAD OF 110 NM ENVELOPE AT TAU 72. HOWEVER, SPATIAL DISPERSION MAGNIFIES SIGNIFICANTLY IN THE EXTENDED PROJECTION, GENERATING A 340 NM CROSS-TRACK SPREAD BY THE FINAL FORECAST TAU. WITHIN THIS LATE-STAGE ENVELOPE DIVERGENCE, NAVGEM FUNCTIONS AS THE PRIMARY OUTLIER BY DEPICTING A SHARPER RECURVATURE PATH IN CLOSER PROXIMITY TO OKINAWA, WHEREAS THE MAJORITY OF THE DYNAMICAL CONSENSUS CLUSTERS FIRMLY ALONG A VECTOR ORIENTED NORTH OF TAIWAN. CONSEQUENTLY, THE JTWC EXTENDED TRACK TRAJECTORY IS ISSUED WITH MEDIUM CONFIDENCE. WITH RESPECT TO INTENSITY, THE HIGH-RESOLUTION MESOSCALE HAFS MODEL HIGHLIGHTS A BRIEF PHASE OF MODEST INTENSIFICATION BETWEEN TAU 36 AND TAU 48. CONVERSELY, THE BROADER DYNAMICAL CONSENSUS ENVELOPE FAVORS A PROLONGED, GRADUAL DECAY PHASE PRECEDED BY INITIAL INTENSITY MAINTENANCE. WEIGHING THE HIGHLY FAVORABLE MESOSCALE ENVIRONMENT AND THE AFOREMENTIONED HAFS GUIDANCE, THE JTWC OFFICIAL INTENSITY PROGNOSIS IS ANCHORED ALONG THE UPPER BOUNDARY OF THE MULTI-MODEL CONSENSUS. THIS REFLECTS THE PROBABILITY OF MINOR NEAR-TERM DEEPENING THROUGH TAU 36 FOLLOWING A BRIEF RELAXATION. BEYOND TAU 36, NEARLY ALL MEMBERS OF THE AVAILABLE NUMERICAL CONSENSUS UNANIMOUSLY AGREE UPON A STEADY AND CONTINUOUS WEAKENING TREND. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN