WDPN32 PGTW 262100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 18W (NORU) WARNING NR 020// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.9N 113.9E INITIAL INTENSITY: 90 KTS GEOGRAPHIC REFERENCE: 418 NM WEST-NORTHWEST OF MANILA, PHILIPPINES MOVEMENT PAST 6 HOURS: WESTWARD AT 17 KTS SIGNIFICANT WAVE HEIGHT: 37 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS INDICATES IMPROVING DEEP CONVECTIVE BANDING WRAPPING IN FROM THE SOUTH AND WEST QUADRANTS, WITH A SMALL EYE FEATURE THAT IS PARTLY CLOUD-FILLED. AN EARLIER 261654Z GMI 89GHZ MICROWAVE IMAGE REVEALS CONVECTIVE BANDING WRAPPING INTO WITH APPEARS TO BE A MICROWAVE EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON EIR IMAGERY AND THE GMI MICROWAVE IMAGERY. THE INITIAL INTENSITY OF 90 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE CURRENT IMPROVED CONVECTIVE STRUCTURE AS WELL AS A COMBINATION OF AGENCY OBJECTIVE AND SUBJECTIVE DVORAK INTENSITY ESTIMATES, PGTW T5.5, RJTD T4.5, ALONG WITH CMISS ADT UP TO 90 KTS. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE TO THE NORTH AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS RJTD: T4.5 - 77 KTS KNES: T5.0 - 90 KTS CIMSS SATCON: 73 KTS AT 261803Z CIMSS ADT: 90 KTS AT 261740Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH 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: TY 18W (NORU) IS BEGINNING TO RAPIDLY INTENSIFY AS ENVIRONMENTAL CONDITIONS ARE FAVORABLE WITH LOW VERTICAL WIND SHEAR, WARM SEA SURFACE TEMPERATURES, AND STRONG RADIAL OUTFLOW. TY 18W IS FORECAST TO TRACK WESTWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING INFLUENCE OF THE STR POSITIONED TO THE NORTH, BEFORE MAKING LANDFALL INTO CENTRAL VIETNAM WITHIN THE NEXT 24-36 HOURS. DUE TO FAVORABLE ENVIRONMENTAL CONDITIONS THE SYSTEM HAS A SHORT DURATION OVER WARM WATER BEFORE REACHING A MAXIMUM PEAK OF 110 KNOTS BY TAU 12. AFTER TAU 24, THE SYSTEM WILL BEGIN TO WEAKEN AS VERTICAL WIND SHEAR INCREASES AND THE SYSTEM TRACKS OVER SOUTHEAST ASIA WITH DISSIPATION EXPECTED BY TAU 72. MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT REGARDING THE TRACK FORECAST, WITH THE EXCEPTION OF THE NAVGEM TRACKER. THIS LENDS HIGH CONFIDENCE IN THE JTWC TRACK FORECAST THROUGH OUT THE FORECAST. THE OVERALL CONFIDENCE IN THE JTWC INTENSITY FORECAST IS MEDIUM DUE TO UNCERTAINTY IN THE MODEL GUIDANCE MAX INTENSITY OVER THE NEXT 24 HOURS. THE BULK OF THE INTENSITY GUIDANCE INDICATES A RE-INTENSIFICATION PHASE WITH HWRF INDICATING A PEAK OF 110 KNOTS AT TAU 12 AND COAMPS-TC A PEAK OF 100 KNOTS. AS WELL AS THE UNCERTAINLY DUE TO LAND INTERACTION AFTER TAU 24. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: MEDIUM// NNNN