170300Z POSITION NEAR 19.3N 105.0E. TROPICAL STORM 20W (BEBINCA), LOCATED APPROXIMATELY 99 NM SOUTH- SOUTHWEST OF HANOI, VIETNAM, HAS TRACKED WEST-SOUTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A WEAKENING SYSTEM WITH STRONG NORTHEASTERLY SHEAR BEGINNING TO DECOUPLE THE LOW LEVEL CIRCULATION FROM THE MASS OF DEEP CONVECTION. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE AFOREMENTIONED MULTISPECTRAL IMAGERY AS WELL AS SURFACE OBSERVATIONS IN THE REGION. A 162234Z SSMIS 37 GHZ IMAGE SUPPORTS THIS POSITION AND REVEALS THAT THE LLCC IS DISPLACED TO THE EASTERN EDGE OF THE DEEP CONVECTION. THE INITIAL INTENSITY WAS ESTIMATED AT 50 KNOTS BASED ON EXPECTED WEAKENING AND THE LACK OF STRONG WINDS FROM ANY LOCAL OBSERVATIONS. UPPER-LEVEL ANALYSIS REVEALS MODERATE TO STRONG VERTICAL WIND SHEAR AND STRONG DIFFLUENT EQUATORWARD FLOW. TS 20W IS OVERLAND TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH AND IS EXPECTED TO CONTINUE WESTWARD UNTIL DISSIPATION BY TAU 36 DUE TO HIGH VWS AND LAND INTERACTION. NUMERICAL MODEL GUIDANCE REMAINS IN FAIRLY GOOD AGREEMENT; THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. REFER TO TROPICAL STORM 21W (RUMBIA) FINAL WARNING ON THAT SYSTEM. REFER TO TYPHOON 22W (SOULIK) WARNINGS (WTPN35 PGTW) FOR SIX-HOURLY UPDATES.
