WDPN32 PGTW 190300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (TALIM) WARNING NR 06// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 06W (TALIM), LOCATED APPROXIMATELY 165 NM SOUTH-SOUTHEAST OF HONG KONG, HAS TRACKED EAST-NORTHEASTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH CURVED, DEEP CONVECTIVE BANDING LIMITED TO THE SOUTHERN SEMI-CIRCLE. AS SHOWN IN THE ANIMATED WATER VAPOR IMAGERY, THIS DISPLACEMENT OF DEEP CONVECTION IS DUE TO MODERATE TO STRONG, NORTHERLY VERTICAL WIND SHEAR (VWS) ASSOCIATED WITH STRONG UPPER-LEVEL RIDGING OVER SOUTHERN CHINA. THERE IS GOOD CONFIDENCE IN THE CURRENT POSITION BASED ON THE PARTIALLY EXPOSED LLCC IN MSI. THE INITIAL INTENSITY WAS BASED ON THE PGTW DVORAK ESTIMATE OF 45 KNOTS. TS 06W HAS INCREASED IN TRANSLATION SPEED ALONG THE EXTENSION OF A LOW- TO MID- LEVEL STEERING RIDGE POSITIONED TO THE SOUTH. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 06W IS FORECAST TO CONTINUE TO ACCELERATE AS THE SUBTROPICAL RIDGE (STR) BUILDS SOUTH OF OKINAWA. VERTICAL WIND SHEAR IS EXPECTED TO RELAX SLIGHTLY BUT WILL OVERALL REMAIN HIGH THROUGHOUT THE LIFESPAN OF THE SYSTEM. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE EXCEPTION OF THE UKMO TRACKER, WHICH IS SLOWER AND ERRONEOUSLY TRACKS THE SYSTEM OVER NORTHERN KYUSHU, INTO THE STRONG WESTERLY JET. THE SYSTEM IS EXPECTED TO BEGIN EXTRATROPICAL TRANSITION (ETT) NORTHEAST OF TAIWAN AS IT BEGINS TO INTERACT WITH THE BAROCLINIC ZONE AND ENCOUNTERS INCREASING VWS AND COOLER SST. THE SYSTEM SHOULD FULLY TRANSITION INTO AN EXTRATROPICAL SYSTEM AS IT REACHES KYUSHU. THERE IS A POSSIBILITY DUE TO THE EXPECTED STRONG VERTICAL WIND SHEAR AND LAND INTERACTION THROUGH THE TAIWAN STRAIT, THE SYSTEM COULD WEAKEN MORE THAN EXPECTED. NOGAPS IS CURRENTLY THE ONLY MODEL TO WEAKEN AND DISSIPATE THE LLCC. C. IN THE EXTENDED TAUS, TS 06W IS FORECAST TO ACCELERATE QUICKLY EASTWARD UNDER THE STRONG WESTERLY FLOW AS AN EXTRA-TROPICAL SYSTEM. MODEL GUIDANCE REMAINS IN GOOD AGREEMENT FOR THE SYSTEM TO TRACK SOUTH OF TOKYO, JAPAN; THEREFORE, THERE IS HIGH CONFIDENCE IN THE OVERALL FORECAST TRACK.// NNNN