WDPN31 PGTW 230900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (IN-FA) WARNING NR 029// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 24.6N 125.1E INITIAL INTENSITY: 80 KTS GEOGRAPHIC REFERENCE: 185 NM SOUTHWEST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 04 KTS SIGNIFICANT WAVE HEIGHT: 38 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A SLIGHT IMPROVEMENT IN STRUCTURE WITH A LARGE, 60NM EYE AND SPIRAL BANDING. ANIMATED RADAR IMAGERY AND A 230518Z AMSR2 89GHZ MICROWAVE IMAGE INDICATE A BREAK IN THE EYEWALL, WHICH IS BECOMING MORE OBLONG OVER THE PAST FEW HOURS. DUE TO THE LARGE EYE, THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE. THE INITIAL INTENSITY OF 80 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE PGTW DVORAK ESTIMATE. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) CENTERED JUST OFF THE EAST COAST OF NORTH KOREA. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS RJTD: T5.0 - 90 KTS RCTP: T4.0 - 65 KTS KNES: T4.0 - 65 KTS CIMSS ADT: 59 KTS AT 230540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 0-5 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM 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 09W IS TRACKING SLOWLY ALONG THE SOUTHWESTERN PERIPHERY OF THE STR AND IS FORECAST TO TRACK NORTH-NORTHWESTWARD THROUGH TAU 36 THEN GRADUALLY TURN WESTWARD UNDER AN EXTENSION OF THE STR TO THE NORTH. SLIGHT INTENSIFICATION TO 85 KNOTS IS EXPECTED IN THE SHORT-TERM THEN GRADUAL WEAKENING AS TY 09W APPROACHES THE CHINA COAST. NEAR TAU 72, THE SYSTEM WILL SLOW AS A MAJOR SHORTWAVE TROUGH DIGS OVER EASTERN CHINA AND WILL TRACK OVERLAND LEADING TO RAPID WEAKENING AND EVENTUAL DISSIPATION DUE TO INTERACTION WITH LAND. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN BETTER AGREEMENT SUPPORTING THE JTWC FORECAST TRACK WITH MEDIUM CONFIDENCE ALTHOUGH NAVGEM REMAINS THE SOLE OUTLIER WITH A TRACK NORTH OF SHANGHAI. THE ECMWF ENSEMBLE (EPS) ALSO SUPPORTS THE JTWC TRACK FORECAST WITH A HIGH PROBABILITY. THERE IS MEDIUM CONFIDENCE IN THE JTWC INTENSITY FORECAST WITH THE BULK OF THE INTENSITY GUIDANCE INDICATING A SLIGHT INTENSIFICATION THEN STEADY WEAKENING AFTER TAU 24. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN