WDPN31 PGTW 192100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (IN-FA) WARNING NR 015// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 24.2N 131.2E INITIAL INTENSITY: 55 KTS GEOGRAPHIC REFERENCE: 230 NM SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 03 KTS SIGNIFICANT WAVE HEIGHT: 30 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS SUBSTANTIAL DRY AIR ENTRAINMENT WRAPPING INTO THE WESTERN SEMICIRCLE OF TS 09W AND RETARDING DEVELOPMENT. THE SYSTEM HAS MAINTAINED GOOD ORGANIZATION, HOWEVER, AND THERE REMAINS A STRONG CORE. THE SUBTROPICAL RIDGE (STR) HAS SETTLED OVER JAPAN AND STRENTGHENED AND IS NOW PUSHING THE SYSTEM SLOWLY AND STEADILY TO THE WEST-NORTHWEST. THE SLOW MOVEMENT OF THE SYSTEM IS CHURNING UP COOLER WATERS, ALSO LIMITING INTENSIFICATION. THE SYSTEM IS ASSESSED AT 55 KNOTS BASED ON A SATCON MEMBER CONSENSUS OF 53KTS. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: THE SUBTROPICAL RIDGE, WHICH IS BUILDING AND SETTLING OVER MAINLAND JAPAN AND EXTENDING SOUTHWARD AS FAR AS THE RYUKUS. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS RJTD: T3.0 - 45 KTS RCTP: T3.5 - 55 KTS KNES: T3.5 - 55 KTS CIMSS ADT: 37 KTS AT 191740Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 5-10 KTS SST: 28-29 CELSIUS OUTFLOW: MODERATE POLEWARD OTHER FACTORS: THE SLOW MOVEMENT OF TS 09W IS CHURNING UP COOLER WATERS FROM BELOW, ALSO ACTING TO IMPEDE DEVELOPMENT. 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: THE SUB TROPICAL RIDGE WILL CONTINE TO DRIVE TS 09W STEADILY WEST-NORTHWESTWARD THROUGH TAU 72. ANIMATED WATER VAPOR IMAGERY REVEALS A DEEPING TROUGH MOVING OFF OF SHANGHAI THAT IS INCREASING UPPER LEVEL CONVERGENCE ALONG TRACK. AFTER TAU 72, TS 09W WILL DRIFT POLEWARD AS IT TRACKS ALONG THE SOUTHWESTERN PERIPHERY OF THE STR. TS 09W SHOULD STEADILY INTENSIFY TO ITS PEAK OF NEAR 90 KTS, REACHING ITS MAXIMUM INTENSITY OVER AND JUST WEST OF THE SOUTHERN RYUKUS. MODEL DISCUSSION: CONFIDENCE IN THE MID-TO-LONG RANGE OF THE FORECAST IS INCREASING AS THE STR ENTRENCHES ITSELF OVER JAPAN AND AN UPPER LEVEL COLD CORE LOW OVER THE WEST SEA THAT WAS PREVIOUSLY MUDDLING THE FORECAST DRIFTS FURTHER OUT OF INCLUENCE. MODEL GUIDANCE DIVERGES IN THE LATER TAUS, WITH A LARGE SPREAD AND SOME MEMBERS OF CONSENSUS STEERING THE SYSTEM CLOSER TO TAIWAN. CONFIDENCE IN THE INTENSITY FORECAST IS IMPROVING, HOWEVER, AS EACH CONSECUTIVE FIX CYCLES VERIFY THE EFFICACY OF THE PREDICTIONS AND THE UPSTREAM ENVIRONMENT IS BECOMING LESS COMPLEX. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN