WDPN31 PGTW 210300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (DUJUAN) WARNING NR 016// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION 01W (DUJUAN), LOCATED APPROXIMATELY 667 NM SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST- NORTHWESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS FLARING CONVECTION NEAR THE LOW LEVEL CIRCULATION (LLC), INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED UPON THE MSI LOOP AND A 210114Z ASCAT METOP-B IMAGE. THE INITIAL INTENSITY OF 30KTS IS BASED ON THE AFOREMENTIONED ASCAT IMAGE ALONG WITH DVORAK ESTIMATES OF T2.0/30KTS FROM PGTW AND RJTD. THE ADVANCED DVORAK TECHNIQUE (ADT) IS SLIGHTLY HIGHER WITH DVORAK OBJECTIVE ESTIMATE OF T3.0/45KTS. ANALYSIS INDICATES WARM (29- 30C) ALONG-TRACK SST AND ROBUST WEST AND POLEWARD OUTFLOW ALOFT. A SLIGHT DECREASE IN VWS HAS ENHANCED THE STRUCTURE OF CONVECTION NEAR THE LLC DUE TO THE STORM MOTION MOVING MORE IN-PHASE WITH THE MID AND UPPER LEVEL WIND FLOW. THE WARM MOIST AIR AHEAD OF THE TD IS CONTINUALLY OVERRUNNING THE COLDER NORTHEASTERLY WIND IN THE PHILIPPINE SEA INCREASING THE INSTABILITY AND CONVECTION. THE CYCLONE CONTINUES TO TRACK NORTHWESTWARD AS THE SUBTROPICAL RIDGE (STR) STEERS IT TOWARDS THE PHILIPPINE ISLANDS. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE IN THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TD 01W WILL CONTINUE TRACKING NORTHWESTWARD AS THE STEERING STR TO THE NORTHEAST BUILDS, THE SYSTEM WILL MAKE INITIAL LANDFALL OVER SAMAR, PHILIPPINES, JUST AFTER TAU 24 AND THEN ENTER THE SIBUYAN SEA AND ENCOUNTER COOLER 26-27C SSTS. AFTER TAU 24, HIGH RELATIVE VWS COMBINED WITH THE RUGGED TERRAIN OF THE MULTIPLE ISLANDS WILL ERODE THE TD TO DISSIPATION BY TAU 48, POSSIBLY SOONER. NUMERICAL MODELS DIVERGE SIGNIFICANTLY TO 300NM+ BY TAU 48. THIS INDICATES UNCERTAINTY IN THE MODELS TRACKING A WEAK VORTEX, LENDING OVERALL LOW CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN