MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (NOUL) WARNING NR 011// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 13W (NOUL), LOCATED APPROXIMATELY 38 NM NORTH- NORTHWEST OF DA NANG, VIETNAM, HAS TRACKED WESTWARD AT 19 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION OVER AN OBSCURED LOW-LEVEL CIRCULATION CENTER (LLCC). A 172358Z SSMIS 91GHZ MICROWAVE IMAGE INDICATES DEEP CONVECTIVE BANDING WRAPPING INTO AN ELONGATED LLCC, WHICH SUPPORTS THE INITIAL POSITION WITH FAIR CONFIDENCE. THE SYSTEM MADE LANDFALL JUST NORTH OF HUE, VIETNAM AT ABOUT 18/0100Z AND HAS BEGUN TO TRACK INLAND. 18/0130Z SURFACE WINDS AT HUE (VVPB) INDICATED WEST-NORTHWESTERLY WINDS AT 20 KNOTS GUSTING TO 35 KNOTS WITH A MINIMUM SLP NEAR 989MB. DUE TO A SLIGHT WEAKENING TREND, THE INITIAL INTENSITY IS ASSESSED AT 45 KNOTS BASED ON A PGTW DVORAK CURRENT INTENSITY ESTIMATE OF 3.0 (45 KNOTS). ENVIRONMENTAL ANALYSIS INDICATES PERSISTENT NORTHEASTERLY VERTICAL WIND SHEAR OF 15-20 KNOTS OFFSET BY VIGOROUS EQUATORWARD OUTFLOW AND WARM SST VALUES (31C). TS NOUL CONTINUES TO TRACK ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS NOUL WILL TRACK WESTWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING INFLUENCE OF THE STR ENTRENCHED TO THE NORTH. THE SYSTEM IS FORECAST TO DISSIPATE AS IT TRACKS FURTHER INLAND OVER MOUNTAINOUS TERRAIN. NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN