WDPN31 PGTW 070300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 15E (NOLO) WARNING NR 066// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 25.3N 164.0E INITIAL INTENSITY: 75 KTS GEOGRAPHIC REFERENCE: 388 NM SOUTH-SOUTHEAST OF WAKE ISLAND MOVEMENT PAST 6 HOURS: WESTWARD AT 22 KTS SIGNIFICANT WAVE HEIGHT: 33 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAPIDLY DEGRADED VORTEX STRUCTURE, CHARACTERIZED BY A COLLAPSING AND INCREASINGLY ASYMMETRIC CENTRAL DENSE OVERCAST (CDO). THE INNER CORE OF THE CDO REMAINS REMARKABLY RESILIENT; HOWEVER, IT EXHBITS PRONOUNCED ZONAL ELONGATION IN RESPONSE TO PERSISTENT EASTERLY VERTICAL WIND SHEAR (VWS). THE LATEST HIGH-RESOLUTION MICROWAVE PASS, A 061918Z WSF-M COLOR-ENHANCED IMAGE, REVEALED THE LAST SATELLITE EVIDENCE OF AN UPPER-LEVEL EYE SIGNATURE COINCIDENT WITH THE INITIATION OF VERTICAL VORTEX DECOUPLING. THE INITIAL POSITION IS ASSESSED WITH LOW CONFIDENCE, DERIVED FROM AN EXTENDED DOWNSTREAM EXTRAPOLATION OF EARLIER MICROWAVE FIXES. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE, ALIGNED WITH THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES OUTLINED BELOW. ENVIRONMENTAL CONDITIONS ARE UNFAVORABLE FOR TROPICAL DEVELOPMENT, DOMINATED BY STRONG AND PERSISTENT EASTERLY SHEAR. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR). AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS RJTD: T4.5 - 77 KTS RCTP: T4.5 - 77 KTS PHFO: T4.5 - 77 KTS CIMSS SATCON: 78 KTS AT 062100Z CIMSS ADT: 69 KTS AT 062330Z CIMSS AIDT: 86 KTS AT 062330Z CIMSS D-MINT: 77 KTS AT 062239Z CIMSS D-PRINT: 72 KTS AT 070030Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE VWS: 25-30 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE EQUATORWARD ANALYSIS CONFIDENCE: INITIAL POSITION: LOW 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: TYPHOON (TY) 15E (NOLO) CONTINUES TO TRANSLATE WESTWARD AT A HIGH VELOCITY ALONG THE STEEP PRESSURE GRADIENT ON THE EQUATORWARD SIDE OF THE EXPANSIVE STR CENTERED TO THE NORTH. 15E WILL CONTINUE TRACKING WEST-NORTHWESTWARD THROUGH TAU 36, DECELERATING AFTER TAU 24 AS IT TRANSITS INTO THE WEAKENED STEERING GRADIENT ALONG THE SOUTHWESTERN PERIPHERY OF THE STR. THE CYCLONE WILL SLOW TO APPROXIMATELY 7 KNOTS BY TAU 60 AS IT APPROACHES THE RIDGE AXIS. THE SYSTEM IS FORECAST TO INTERSECT THE RIDGE AXIS BY TAU 72, THEREAFTER EXECUTING RECURVATURE AND ACCELERATING NORTHEASTWARD BY THE LATER FORECAST TAUS. REGARDING INTENSITY: PERSISTENT NORTHEASTERLY VWS WILL WORK TO WEAKEN 15E FOR THE NEXT 24 TO 36 HOURS. AS THE SYSTEM APPROACHES THE RIDGE AXIS, SHEAR IS FORECAST TO RELAX SLIGHTLY, FACILITATING A BRIEF PERIOD OF STABILIZATION OR MODEST RE- INTENSIFICATION AS 15E COUPLES WITH THE OUTFLOW INTO A POLAR JET MAX TRANSITING TO THE NORTH. POST-TAU 72, HOWEVER, ACCELERATING SHEAR COMPILED WITH A SHARP DECREASE IN SSTS WILL DRIVE RAPID DECAY THROUGH THE REMAINDER OF THE FORECAST. THERE REMAINS A SIGNIFICANT AMOUNT OF UNCERTAINTY IN THE TRACK FORECAST, CRITICALLY MODULATED BY BINARY INTERACTION WITH TS 27W, CURRENTLY POSITIONED APPROXIMATELY 650 NM SOUTH-SOUTHWEST OF 15E. THE SEPARATION DISTANCE IS PROJECTED TO HOVER NEAR 600 NM THROUGHOUT THE FORECAST PERIOD. THE PRIMARY DYNAMICAL DIVERGENCE CENTERS ON THE LONGITUDE OF THE RECURVATURE POINT, WHICH IS A DIRECT FUNCTION OF THE COUPLING MAGNITUDE WITH TS 27W. THE ECMWF AND GFS DYNAMICAL SUITES DELAY RECURVATURE, EXTENDING THE WESTWARD TRACK COMPONENT SIGNIFICANTLY. CONVERSELY, AI-ML SOLUTIONS PROJECT MINIMAL BINARY COUPLING AS 15E OUTRACES TS 27W, PROMOTING AN EARLIER POLEWARD RECURVATURE ROUTE SITUATED FARTHER EAST. THE JTWC FORECAST STRONGLY FAVORS THE PROGRESSIVE AI-ML SCENARIO. MODEL DISCUSSION: TRACK GUIDANCE DEPICTS SIGNIFICANT UNCERTAINTY, EXHIBITING PRONOUNCED CROSS-TRACK DISPERSION. AS 15E APPROACHES THE RIDGE AXIS AT TAU 72, THE GUIDANCE PACKAGE IS FANNED ACROSS A 400 NM ENVELOPE, WITH THE AI CONSENSUS (AICN) AND EC-AIFS RESIDING ON THE EASTERN (INNER) PERIPHERY OF THE RECURVATURE PATH, WHILE THE DETERMINISTIC ECMWF AND ECEPS MEAN DEFINE THE WESTERN (OUTER) FLANK. THROUGH TAU 120, CROSS-TRACK ANOMALIES NARROW SLIGHTLY, ALTHOUGH ALONG-TRACK TRANSLATION SPEED BIAS BECOMES THE PREVALENT UNCERTAINTY DRIVER, STRETCHING TO OVER 500 NM BETWEEN THE FAST GFS AND THE SLOW MULTI-MODEL CONSENSUS MEAN. THE AI-ML RECURVATURE TRACKS ARE CLUSTERED ON THE EASTERN PERIPHERY OF THE ENVELOPE, MEDIAN TO THE ACCELERATING ALONG-TRACK OUTLIERS. THE ECMWF AND GFS EXCURSION REMAINS SOUTH-SOUTHWEST OF THE GROUP THROUGH TAU 120. THE JTWC TRACK IS POSITIONED NEAR THE GOOGLE DEEPMIND TRACKER WITH LOW CONFIDENCE. INTENSITY GUIDANCE IS IN GOOD AGREEMENT, WITH THE ENTIRE MODEL SUITE PROJECTING AN INITIAL DECAY PHASE THROUGH TAU 24, A TEMPORARY STRUCTURAL STABILIZATION THROUGH TAU 48, AND ACCELERATED DECAY POST- TAU 72. FORECAST CONFIDENCE: TRACK 00-72 HR: LOW TRACK 72-120 HR: LOW INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN