WDPN32 PGTW 082100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR 051// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 30.5N 129.8E INITIAL INTENSITY: 55 KTS GEOGRAPHIC REFERENCE: 156 NM SOUTH OF SASEBO, JAPAN MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 07 KTS SIGNIFICANT WAVE HEIGHT: 25 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS DEEP CONVECTIVE BANDS WRAPPING INTO A LARGE, EXPOSED LOW LEVEL CIRCULATION (LLC) THAT HAS RELATIVELY BECOME SMALLER OVER THE PAST 12HRS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE LLC FEATURE IN THE EIR LOOP AND ALSO ON A COMPOSITE RADAR LOOP. THE INITIAL INTENSITY IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON THE OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE SLIGHT 6-HR WRAP IMPROVEMENT. ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT WITH GOOD VENTILATION AND LOW VWS ALOFT, AND WARM SST OFFSET BY SUBSIDENCE ALONG THE NORTHEAST SIDE AND DRY AIR ENTRAINMENT IN THE LOWER LEVELS. INITIAL WIND RADII BASIS: PERSISTENCE. CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS RJTD: T3.5 - 55 KTS KNES: T3.5 - 55 KTS CIMSS ADT: 32 KTS AT 081730Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 0-5 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG EQUATORWARD OTHER FACTORS: MODERATE POLEWARD OUTFLOW. 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: TS 06W WILL CONTINUE TO TRACK NORTHWESTWARD TOWARD THE KOREAN PENINSULA VIA THE KOREAN STRAIT UNDER THE STEERING STR, MAKING LANDFALL WEST OF BUSAN AROUND TAU 30, THEN TRACK JUST TO THE WEST OF SEOUL BY TAU 48 BEFORE CROSSING INTO NORTH KOREA. THE MARGINALLY FAVORABLE ENVIRONMENT WILL PROMOTE A SLIGHT INTENSIFICATION TO A PEAK OF 60KTS AT TAUS 12-24. AFTERWARD, INTERACTION WITH THE RUGGED TERRAIN OF THE KOREAN PENINSULA COMBINED WITH RAPIDLY INCREASING VWS WILL LEAD TO RAPID DETERIORATION TO 35KTS NEAR SEOUL THEN TO EVENTUAL DISSIPATION BY TAU 72 AFTER THE SYSTEM CROSSES INTO NORTH KOREA. MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST. DUE TO THE VARIABILITY OF LAND PASSAGE, THERE IS ONLY OVERALL MEDIUM CONFIDENCE IN THE INTENSITY FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: MEDIUM// NNNN