WDPN31 PGTW 271500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (SURIGAE) WARNING NR 018// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 25.9N 129.1E INITIAL INTENSITY: 125 KTS GEOGRAPHIC REFERENCE: 76 NM EAST-SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 45 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON (TY) 25W (SURIGAE) AS A ROBUST AND POWERFUL SYSTEM THAT RECENTLY RAPIDLY INTENSIFIED TO 125 KTS. 25W INTENSIFIED 50 KTS WITHIN THE PAST 24 HOURS -- STRENGTHENING FROM 75 KTS AT 261200Z TO 125 KTS AT 271200Z -- WITH AN INTENSIFICATION OF 30 KTS IN JUST THE PAST 12 HOURS ALONE. THIS SCALE OF INTENSIFICATION WAS UNEXPECTED, GIVEN THAT 25W STILL STRUGGLED TO ESTABLISH A CLOUD-FREE EYE AS RECENTLY AS 6 HOURS AGO. THE ENVIRONMENT REMAINS HIGHLY FAVORABLE, CHARACTERIZED BY LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS), WARM (29-30 C) SEA SURFACE TEMPERATURES, AND ROBUST DUAL-CHANNEL OUTFLOW. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE WELL-DEFINED EYE IN ANIMATED EIR. THE INITIAL INTENSITY OF 125 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE STRONG AGREEMENT BETWEEN THE AGENCY DVORAK FIXES AND CIMSS AUTOMATED INTENSITY ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) POSITIONED TO THE EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T6.5 - 127 KTS RJTD: T6.5 - 127 KTS RCTP: T6.5 - 127 KTS CIMSS SATCON: 125 KTS AT 271210Z CIMSS ADT: 129 KTS AT 271210Z CIMSS AIDT: 122 KTS AT 271300Z CIMSS D-MINT: 115 KTS AT 271034Z CIMSS D-PRINT: 124 KTS AT 271210Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG DUAL-CHANNEL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: TY 25W UNDERWENT UNEXPECTEDLY RAPID INTENSIFICATION TO 125 KTS. THE FORECAST HAS BEEN UPDATED TO REFLECT HIGHER INTENSITIES AS THE STORM WEAKENS. FORECAST DISCUSSION: TY 25W IS FORECAST TO CONTINUE TRACKING ALONG THE NORTHWESTERN EXTENT OF THE STR CENTERED TO ITS EAST AND ACCELERATE POLEWARD FOR THE DURATION OF THE FORECAST PERIOD. ADDITIONALLY, 25W IS EXPECTED TO REMAIN RELATIVELY COMPACT FOR THE REST OF ITS LIFESPAN. BEGINNING AROUND TAU 24, VWS IS EXPECTED TO INCREASE TO ABOUT 20 KTS AND INDUCE DRY AIR ENTRAINMENT FROM THE NORTHERN SEMICIRCLE, THUS BEGINNING THE STEADY WEAKENING TREND FROM TAU 24 ONWARD. 25W IS EXPECTED TO CROSS THE 26C ISOTHERM BETWEEN TAU 72-96, NEARLY SIMULTANEOUS TO THE SYSTEM ENTERING THE BAROCLINIC ZONE AND BEGINNING JET INTERACTION. VWS IS EXPECTED TO INCREASE TO OVER 30 KTS BY TAU 72, FURTHER COMPOUNDING WEAKENING. 25W IS FORECAST TO BEGIN EXTRATROPICAL TRANSITION BETWEEN TAU 72 AND COMPLETE TRANSITION NO LATER THAN TAU 96. REGARDING INTENSITY, 25W MAY CONTINUE TO INTENSIFY FOR THE NEXT 6-12 HOURS, BUT IS CURRENTLY FORECAST TO BEGIN IT'S TERMINAL WEAKENING TREND AT TAU 12. SHOULD 25W CONTINUE TO INTENSIFY BEYOND TAU 12, THE TERMINAL WEAKENING COULD BE FURTHER DELAYED. REGARDLESS, 25W IS FORECAST TO WEAKEN AS IT TRACKS POLEWARD INTO INCREASINGLY HOSTILE CONDITIONS BEFORE ULTIMATELY BECOMING AN EXTRATROPICAL SYSTEM. MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN DECENT AGREEMENT UNTIL TAU 36. AT THAT POINT, OUTLIERS BEGIN TO EMERGE FROM THE PACK, INCLUDING GFS. THE GEFS MEAN, AND ECMWF. THOSE MODELS DEPICT A SIGNIFICANTLY SLOWER AND A SLIGHTLY MORE EQUATORWARD TRACK COMPARED TO OTHER PHYSICS-BASED MODELS AND THE AI-BASED EXPERIMENTAL MODELS. THE ALONG-TRACK SPREAD COMPOUNDS BETWEEN TAU 36-96, ULTIMATELY LEADING TO A 730NM ALONG-TRACK SPREAD AT TAU 96 BETWEEN THE FASTEST MODEL (GSM) AND THE SLOWEST MODEL (GFS). GFS IS SIGNIFICANTLY SLOWER DUE TO POSSIBLE BINARY INTERACTION BETWEEN 25W AND A SECOND FUTURE STORM THAT GFS RAPIDLY FORMS NEAR THE MARIANAS ISLANDS. GFS DEPICTS THE SECOND STORM HEAVILY INFLUENCING SURIGAE'S TRACK BEFORE ULTIMATELY ABSORBING 25W. THIS SCENARIO IS CONSIDERED TO BE UNLIKELY, DUE TO THE CONSISTENCY IN AI-BASED MODELS AND OTHER PHYSICS-BASED MODELS THAT DO NOT DEPICT THIS SCENARIO. THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUSES FOR PHYSICS-BASED AND AI-BASED MODELS. DUE TO THE CONSIDERABLE ALONG-TRACK SPREAD THROUGHOUT THE FORECAST PERIOD, THE JTWC TRACK FORECAST IS PLACED WITH MEDIUM CONFIDENCE FROM TAU 0-72 AND LOW CONFIDENCE FROM TAU 72-96. RELIABLE INTENSITY AIDS DID NOT ACCURATELY DEPICT THE RECENT RAPID INTENSIFICATION AND THEREFORE STRUGGLE TO REFLECT THE HIGHER INITIAL INTENSITY IN THE WEAKENING TREND THROUGH TAU 96. THE JTWC INTENSITY FORECAST LIES SLIGHTLY HIGHER THAN THE MULTI-MODEL CONSENSUS THROUGH TAU 48, REFLECTING A STEADY WEAKENING TREND ACCOUNTING FOR THE HIGHER INTENSITIES. AFTER TAU 48, THE JTWC INTENSITY FORECAST IS IN CLOSE AGREEMENT WITH THE MULTI-MODEL CONSENSUS AND THE HAFS-A SOLUTION. DUE TO THE UNFORECASTED RAPID INTENSIFICATION AND RESULTING UNCERTAINTY REGARDING THE INTENSITY FORECAST, THE JTWC INTENSITY FORECAST IS ASSESSED WITH OVERALL LOW CONFIDENCE. FORECAST CONFIDENCE: TRACK 00-72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 00-72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN