MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (ONE) WARNING NR 11// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 123 NM SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED WESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH RAPIDLY DECAYING DEEP CONVECTION SHEARING TO THE NORTHWEST. A 151439Z METOP-A 89GHZ IMAGE REVEALS A WEAKLY-DEFINED LLCC WITH CURVED CONVECTIVE BANDING OVER THE NORTHWEST QUADRANT. A 151352Z ASCAT IMAGE SHOWS AN ELONGATED, DEFINED CIRCULATION WITH 25 TO 30 KNOT WINDS ISOLATED OVER THE NORTHWEST QUADRANT AND 10 TO 15 KNOTS ELSEWHERE. THE CURRENT INTENSITY IS ASSESSED AT 25 KNOTS BASED ON THE AFOREMENTIONED ASCAT IMAGE AND DVORAK ESTIMATES OF 25 KNOTS FROM RJTD, PGTW AND KNES. UPPER-LEVEL ANALYSIS CONTINUES TO INDICATE A MARGINALLY-FAVORABLE ENVIRONMENT WITH BROAD DIFFLUENT FLOW. TD 01W IS TRACKING WESTWARD UNDER THE STEERING INFLUENCE OF THE LOW- TO MID- LEVEL SUBTROPICAL RIDGE TO THE NORTH. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TD 01W WILL CONTINUE TO TRACK WESTWARD TO WEST-SOUTHWESTWARD THROUGH THE FORECAST PERIOD. THE SYSTEM WILL MAKE LANDFALL OVER THE SOUTHERN TIP OF VIETNAM NEAR TAU 12 AND WILL WEAKEN FURTHER AS IT NEARS VIETNAM DUE TO LAND INTERACTION. THE MARGINAL ENVIRONMENT, ALONG WITH LAND INTERACTION, WILL PREVENT THE SYSTEM FROM INTENSIFYING AND LEAD TO ITS COMPLETE DISSIPATION BY THE END OF THE FORECAST PERIOD OR POSSIBLY SOONER. AVAILABLE DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT, LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN