MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W (KAI-TAK) WARNING NR 18// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 14W (KAI-TAK), LOCATED APPROXIMATELY 145 NM SOUTH- SOUTHWEST OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES THAT THE DEEP CONVECTION HAS RE-STRENGTHENED OVER THE LOW LEVEL CIRCULATION CENTER (LLCC) INDICATED BY COOLING CLOUD TOP TEMPERATURES. A 161415Z AMSU-B IMAGE CONTINUES TO INDICATE A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER WITH TIGHTLY-CURVED CONVECTIVE BANDING WRAPPING INTO THE CENTER CONFINED TO THE SOUTHERN SEMI-CIRCLE. UPPER LEVEL ANALYSIS REVEALS THAT THE TUTT CELL THAT WAS POSITIONED TO THE NORTHWEST HAS FILLED OVER THE PAST SIX HOURS AND RAPIDLY TRACKED WEST. THE IMPROVED POLAR OUTFLOW THAT THE TUTT CELL WAS PROVIDING HAS WEAKENED DUE TO THE INCREASING DISTANCE FROM TY 14W. THERE IS ALSO WEAK (05-10 KNOT) VERTICAL WIND SHEAR ACTING UPON THE SYSTEM. THE INITIAL POSITION IS BASED ON RADAR FIXES FROM THE HONG KONG OBSERVATORY AND THE AMSU-B IMAGE WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS HELD AT 65 KNOTS BASED ON DVORAK ESTIMATES OF 65 KNOTS FROM PGTW, KNES AND RJTD. TY 14W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE DEEP SUBTROPICAL RIDGE (STR) POSITIONED OVER SOUTHEAST CHINA. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 14W WILL CONTINUE TO TRACK UNDER THE DOMINANT STR OVER CHINA. MODEL GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU 12 AND THERE IS SLIGHT SPREAD AFTER THAT WITH WBAR BEING THE RIGHTMOST OUTLIER TAKING AN UNLIKELY MORE NORTHERN TRACK AND EGRR BEING THE LEFTMOST OUTLIER TAKING A MORE SOUTHERN COURSE AFTER TAU 24 WHICH IS ALSO UNLIKELY DUE THE DOMINANT STR. TY 14W WILL HOLD INTENSITY FOR THE NEXT 12 HOURS DUE TO A FAVORABLE UPPER LEVEL ENVIRONMENT AND SEA SURFACE TEMPERATURES (28-30 DEGREES CELSIUS) BUT SHOULD THEN WEAKEN SIGNIFICANTLY DUE TO INCREASING INTERACTION WITH LAND AS IT NEARS THE LEIZHOU PENINSULA. AFTER TAU 24, TY 14W WILL RAPIDLY DECAY AS IT TRACKS AWAY FROM THE GULF OF TONKIN AND OVER THE MOUNTAINOUS REGION OF NORTHERN VIETNAM. THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK.// NNNN NNNN