MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 29W (TWENTYNINE) WARNING NR 07// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION 29W (TWENTYNINE), LOCATED APPROXIMATELY 396 NM WEST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED NORTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED SHALLOW AND DISORGANIZED CONVECTION WHICH IS DISPLACED SLIGHTLY TO THE NORTH OF A WEAK LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS BASED ON A CLOUD NOTCH FEATURE SEEN IN AN 071800 HIMAWARI SATELLITE IMAGE. THE INTENSITY OF 25 KNOTS IS BASED ON A PGTW DVORAK ESTIMATE OF T1.0 (25 KNOTS). UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS IN AN AREA OF LOW (5-10 KNOT) VERTICAL WIND SHEAR (VWS) AND POOR OUTFLOW. SEA SURFACE TEMPERATURES ARE ALSO FAVORABLE (28-29 CELSIUS). HOWEVER, PROXIMITY TO THE MALAY PENINSULA IS CUTTING OFF MOISTURE INFLOW AND INHIBITING FURTHER DEVELOPMENT. TD 29W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. NO SIGNIFICANT CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TD 29W WILL CONTINUE TO TRACK NORTHWESTWARD UNDER THE INFLUENCE OF THE STR THROUGHOUT THE FORECAST PERIOD. THE SYSTEM WILL WEAKEN TO 20 KNOTS AS IT MAKES LANDFALL JUST SOUTH OF PRACHUAP KHIRI KHAN, THAILAND, NEAR TAU 3 AND CROSS THE MALAY PENINSULA. AFTER TAU 12, TD 29W WILL EXIT INTO THE ANDAMAN SEA AND INTENSIFY TO 25 KNOTS AS OUTFLOW IMPROVES, PEAKING TO 30 KNOTS BY TAU 36. AFTER TAU 48 NUMERICAL MODEL GUIDANCE INDICATES THAT TD 29W WILL ENCOUNTER STRONG VERTICAL WIND SHEAR AND WILL BE ABSORBED INTO THE CYCLONIC FLOW PRESENT IN THE BAY OF BENGAL. DUE TO THE WEAK NATURE OF THE SYSTEM NUMERICAL MODELS ARE HAVING A DIFFICULT TIME TRACKING THE SYSTEM. THEREFORE THERE IS LOW CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN NNNN