WDPN31 PGTW 171500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (KAI-TAK) WARNING NR 21// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 14W (KAI-TAK), LOCATED APPROXIMATELY 120 NM EAST-NORTHEAST OF HANOI, VIETNAM, HAS TRACKED WESTWARD AT 17 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY AND A 171236Z SSMIS IMAGE DEPICT TIGHTLY-CURVED DEEP CONVECTIVE BANDING WRAPPING INTO A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). BASED ON THIS IMAGERY, THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION AND TRACK MOTION. TS 14W IS CURRENTLY MAKING LANDFALL OVER THE NORTHEAST COAST OF VIETNAM AND HAS WEAKENED SLIGHTLY OVER THE PAST SIX HOURS, THEREFORE, THE INITIAL INTENSITY WAS LOWERED TO TROPICAL STORM STRENGTH AT 60 KNOTS BASED ON AN AVERAGE OF DVORAK ESTIMATES RANGING FROM 55 TO 65 KNOTS. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS KAI-TAK IS FORECAST TO CONTINUE TRACKING WEST- NORTHWESTWARD THROUGH THE PERIOD UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE POSITIONED OVER SOUTHERN CHINA. MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, THEREFORE, THE JTWC FORECAST IS POSITIONED CLOSE TO THE MODEL CONSENSUS. TS 14W IS EXPECTED TO WEAKEN RAPIDLY AFTER TAU 12 AS THE SYSTEM TRACKS INTO NORTHERN VIETNAM AND WILL DISSIPATE BY TAU 24. THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK.// NNNN