WDPN33 PGTW 292100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (KRATHON) WARNING NR 011// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 20.0N 122.3E INITIAL INTENSITY: 105 KTS GEOGRAPHIC REFERENCE: 309 NM SOUTH OF TAIPEI, TAIWAN MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 35 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 22 NM EYE OF TYPHOON 20W (KRATHON) SURROUNDED BY SPIRAL BANDS OF DEEP CONVECTION GENERATED THROUGH STRONG RADIAL OUTFLOW. THE EYE FEATURE HAS BEEN CONTRACTING SINCE THE LAST FORECAST, INDICATING STEADY INTENSIFICATION. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE IN THE EIR LOOP, AS WELL AS A DEFINED LOW LEVEL CIRCULATION FEATURE IN THE 291525Z OCEANSAT-3 PASS. THE INITIAL INTENSITY OF 105 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON AGENCY ESTIMATES AS WELL AS AUTOMATED FIXES LISTED BELOW AND REFLECTS THE 6- HR CONVECTIVE IMPROVEMENT IN THE EIR ANIMATION. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST AND UPPER-LEVEL TROUGHING TO THE NORTH AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS RJTD: T5.5 - 102 KTS RCTP: T6.0 - 115 KTS KNES: T5.5 - 102 KTS CIMSS SATCON: 94 KTS AT 291500Z CIMSS ADT: 119 KTS AT 291730Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH 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 20W (KRATHON) HAS CONCLUDED THE RAPID INTENSIFICATION PHASE, HOWEVER GIVEN REMAINING STRONGLY FAVORABLE ENVIRONMENT IS FORECAST TO CONTINUE A STEADY INTENSIFICATION, BUT AT A SLOWER PACE, REACHING A PEAK OF 120 KTS BY TAU 24. AT THAT TIME, KRATHON WILL BEGIN TURNING TOWARDS TAIWAN AND, THEREFORE, FURTHER INTENSIFICATION WILL BE HINDERED BY LAND INTERACTION AS WELL AS COOLER WATER DUE TO UPWELLING, AS THE TYPHOON SLOWS DOWN. THE SYSTEM IS FORECAST TO WEAKEN TO 85 KTS BY TAU 72, AS IT TRANSITS THROUGH CENTRAL TAIWAN. TERRAIN IMPACTS WILL LEAD TO FURTHER WEAKENING AND THE SYSTEM IS FORECAST TO REEMERGE NORTHEAST OF TAIWAN AND WILL REDUCE TO 70 KTS SYSTEM BY TAU 96. AFTER TAU 96, THE SYSTEM IS FORECAST TO STEADILY WEAKEN, AS IT ENCOUNTERS COOLER WATERS IN THE EAST CHINA SEA. MODEL DISCUSSION: NUMERICAL WEATHER GUIDANCE IS COMING TO A CLOSER AGREEMENT IN REGARDS TO THE TRACK OF THE SYSTEM, WITH SOME UNCERTAINTY IN REGARD TO THE TIMING OF THE TURN PRIOR TO LANDFALL IN TAIWAN. ALL OF THE CONSENSUS MEMBERS, HOWEVER, INDICATE STRONG AGREEMENT IN THE TRACK OVER CENTRAL TAIWAN, WITH NAVGEM BEING THE LEFT OUTLIER PLACED FURTHER TO THE WEST OF THE MAIN GROUPING AND ONLY BRUSHING BY THE WESTERN COAST OF TAIWAN. MAJORITY OF THE REST OF THE MODELS ARE WITHIN A 30 NM CROSS-TRACK SPREAD AS THE SYSTEM MAKES LANDFALL. UNCERTAINTY IS ALSO PRESENT IN THE TRACK GUIDANCE PAST TAIWAN, WITH A MUCH LARGER SPREAD BETWEEN THE NUMERICAL MODELS, MAJORITY OF WHICH ARE TAKING THE TRACK ON PATH TOWARDS SOUTH KOREA. THERE IS ALSO SOME POTENTIAL FOR RE-INTENSIFICATION OVER THE WATERS OF THE EAST CHINA SEA, TOWARDS THE END AND OUTSIDE OF THE FORECAST PERIOD, DEPENDENT ON THE SYSTEMS SPEED AS IT REEMERGES NORTHEAST OF TAIWAN. JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS, SLIGHTLY TO THE EAST TO OFFSET IMPACTS OF THE OUTLYING NAVGEM. IN TERMS OF INTENSITY, JTWC FORECAST IS ON THE HIGHER SIDE OF THE MULTI-MODEL CONSENSUS, GIVEN THE CURRENTLY HIGHLY FAVORABLE ENVIRONMENTAL CONDITIONS. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN