MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (ONE) WARNING NR 03// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 318 NM SOUTH OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 18 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY-EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION SHEARED OVER THE WESTERN SEMI-CIRCLE DUE TO MODERATE (15 TO 20 KNOTS) EASTERLY VERTICAL WIND SHEAR (VWS). A 020600Z HIMAWARI VISIBLE SATELLITE IMAGE SHOWS THE AFOREMENTIONED PARTIALLY-EXPOSED LLCC WITH THE MAJORITY OF THE CONVECTION SHEARED TO THE WEST. THE INITIAL INTENSITY IS ASSESSED AT 30 KNOTS, HEDGED SLIGHTLY ABOVE THE RJTD DVORAK ESTIMATE OF T1.5 (25 KNOTS). TD 01W IS TRACKING WESTWARD ACROSS THE SULU SEA UNDER THE STEERING INFLUENCE OF AN EAST-WEST ORIENTED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TD 01W IS FORECAST TO CONTINUE TRACKING WESTWARD UNDER THE INFLUENCE OF THE STR WHICH IS LOCATED TO THE NORTH AND GRADUALLY INCREASE IN INTENSITY TO 35 KNOTS BY TAU 12. MODERATE VERTICAL WIND SHEAR WILL PREVENT ADDITIONAL INTENSIFICATION. AS TD 01W ENTERS THE SOUTH CHINA SEA IT WILL INITIALLY ENCOUNTER FAVORABLE SEA SURFACE TEMPERATURES (28 TO 29 DEGREES CELSIUS). HOWEVER, AS TD 01W TRACKS WESTWARD IT WILL ENCOUNTER COOLER SEA SURFACE TEMPERATURES WHICH WILL LIMIT DEVELOPMENT. SEA SURFACE TEMPERATURES WILL BECOME UNFAVORABLE (25 DEGREES CELSIUS) BY TAU 48. SHORTLY AFTER TAU 48 TD 01W WILL MAKE LANDFALL OVER SOUTHERN VIETNAM AND SLOW IN FORWARD SPEED. BY TAU 72, TD WILL DISSIPATE OVER VIETNAM DUE TO LAND INTERACTION. NUMERICAL MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH TAU 24. BEYOND TAU 24, THERE IS A LARGE SPREAD IN THE MODEL GUIDANCE AS TD 01W APPROACHES VIETNAM. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO THE LARGE SPREAD IN MODEL SOLUTIONS AFTER TAU 24.// NNNN NNNN