WDPN32 PGTW 260900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 18W (NORU) WARNING NR 018// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.9N 116.9E INITIAL INTENSITY: 80 KTS GEOGRAPHIC REFERENCE: 250 NM WEST-NORTHWEST OF MANILA, PHILIPPINES MOVEMENT PAST 6 HOURS: WESTWARD AT 14 KTS SIGNIFICANT WAVE HEIGHT: 35 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM CONTINUED TO RE-CONSOLIDATE AFTER IT EXITED INTO THE SOUTH CHINA SEA (SCS) FROM LUZON, PHILIPPINES. CENTRAL CONVECTION HAS DEEPENED AND RE-FORMED A 17-NM EYE. CURVED BANDS FEEDING IN FROM THE WEST AND SOUTH HAVE BECOME MORE SOLID. THE INITIAL POSITION WAS BASED ON THE EYE IN A LOW VWS ENVIRONMENT, HENCE NO ADJUSTMENT FOR TILT. THE INITIAL INTENSITY WAS BASED ON THE HIGH END OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND PROPORTIONAL TO THE IMPROVED 6-HR CONVECTIVE STRUCTURE. INITIAL WIND RADII BASIS: PERSISTENCE. CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE TO THE NORTH. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.0 - 90 KTS RJTD: T4.0 - 65 KTS KNES: T4.0 - 65 KTS CIMSS SATCON: 81 KTS AT 260208Z CIMSS ADT: 79 KTS AT 260540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 0-5 KTS SST: 30-31 CELSIUS OUTFLOW: STRONG RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY NORU WILL CONTINUE TO TRACK GENERALLY WESTWARD IN THE SCS WHERE THE WARM WATERS, COMBINED WITH STRONG RADIAL OUTFLOW AND LOW VWS, WILL HELP FUEL A SECONDARY INTENSIFICATION TO A PEAK OF 110KTS BY TAU 36 AS IT APPROACHES CENTRAL VIETNAM. TY 18W WILL MAKE A FINAL LANDFALL SOUTH OF HUE AROUND TAU 42. AFTER LANDFALL, THE RUGGED TERRAIN OF VIETNAM, CAMBODIA, AND THAILAND WILL RAPIDLY WEAKEN THE SYSTEM TO DISSIPATION BY TAU 96. MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY TIGHT AGREEMENT WITH NVGM THE SOLE RIGHT OF TRACK OUTLIER BEGINNING TAU 48, LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST UP TO TAU 72, ADJUSTED SLIGHTLY LEFT OF CONSENSUS TO OFFSET NVGM AFTER TAU 48, THEN LOW CONFIDENCE AFTER TAU 72 DUE TO THE UNCERTAINTY OF PROLONGED LAND INTERACTION. THERE IS ALSO MEDIUM AND LOW CONFIDENCE IN THE INTENSITY FORECAST FOR THE SAME REASON. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: LOW// NNNN