MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (VAMCO) WARNING NR 03// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 19W (VAMCO), LOCATED APPROXIMATELY 141 NM EAST-SOUTHEAST OF DA NANG, VIETNAM, HAS TRACKED WESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS FLARING CENTRAL CONVECTION WITH SLIGHTLY WEAKER DEEP CONVECTIVE BANDING WRAPPING AROUND THE WESTERN PERIPHERY. THE BULK OF DEEP CONVECTION IS DISPLACED TO THE WEST OVER LAND DUE TO PERSISTENT 15 TO 20 KNOT NORTHEASTERLY VERTICAL WIND SHEAR. A 140111Z GPM 89 GHZ MICROWAVE IMAGE SHOWS A WELL DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) WITH FRAGMENTED CONVECTIVE BANDING WRAPPING INTO THE CENTER. THE CURRENT POSITION IS BASED ON THE LLCC IN THE GPM MICROWAVE IMAGE AND SUPPORTED BY A PGTW SATELLITE FIX. THE INITIAL INTENSITY IS HELD AT 35 KNOTS BASED ON A DVORAK INTENSITY ESTIMATE OF T2.5 (35 KNOTS) FROM RJTD. UPPER LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH GOOD DIVERGENT OUTFLOW AND MODERATE VWS. IN ADDITION, SEA SURFACE TEMPERATURES ARE ABOVE 30 CELSIUS. TS 19W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUB-TROPICAL RIDGE (STR) ANCHORED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS VAMCO WILL CONTINUE TO TRACK WESTWARD UNDER THE INFLUENCE OF THE STEERING STR THROUGH THE END OF THE FORECAST PERIOD. ENVIRONMENTAL CONDITIONS WILL ALLOW FOR THE POSSIBILITY OF SLIGHT INTENSIFICATION PRIOR TO MAKING LANDFALL OVER CENTRAL VIETNAM. AFTERWARDS, TS 19W WILL BEGIN TO RAPIDLY WEAKEN DUE TO LAND INTERACTION AS IT TRACKS INLAND. THE SYSTEM IS FORECAST TO FULLY DISSIPATE IN 36 HOURS OR POSSIBLY SOONER. DYNAMIC MODEL GUIDANCE REMAINS IN GOOD OVERALL AGREEMENT LENDING TO HIGH CONFIDENCE IN THE JTWC FORECAST.// NNNN NNNN