MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (NOUL) WARNING NR 004// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 13W (NOUL), LOCATED APPROXIMATELY 260 NM WEST-SOUTHWEST OF MANILA, PHILIPPINES, HAS TRACKED WEST- NORTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS FLARING CONVECTION OBSCURING A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE LOCATION OF THE LLCC IN THE MSI LOOP AS WELL AS THE BANDING FEATURES PRESENT IN 160506Z ATMS 183 GHZ AND 160553Z AMSR2 36GHZ IMAGES. THE INITIAL INTENSITY OF 45 KTS IS PLACED WITH HIGH CONFIDENCE AS WELL BASED ON THE 45 KTS WINDS WRAPPING INTO A LOW LEVEL CIRCULATION PRESENT IN THE SCATTEROMETRY WIND FIELD FROM A 160222Z ASCAT-B PASS AND IS IN AGREEMENT WITH A CIMSS ADVANCED DVORAK TECHNIQUE CURRENT INTENSITY ESTIMATE OF T3.1 (47 KTS). TS NOUL CONTINUES TO TRACK ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST AND THROUGH AN ENVIRONMENT THAT IS MARGINALLY FAVORABLE FOR FURTHER DEVELOPMENT WITH VERY WARM (30-32 CELSIUS) SEA SURFACE TEMPERATURES (SST) AND ROBUST EQUATORWARD OUTFLOW ALOFT OFFSET BY MODERATE TO HIGH (15-25 KTS) VERTICAL WIND SHEAR (VWS) ALONG THE SOUTHWESTERN PERIPHERY OF THE SYSTEM. UPPER LEVEL CONVERGENCE DUE TO THE DEEP EASTERLY FLOW ALOFT ALSO CONTINUES TO STIFLE POLEWARD OUTFLOW AND LIMIT INTENSIFICATION, DESPITE THE CONDUCIVE SSTS. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS NOUL WILL CONTINUE TO TRACK GENERALLY WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR THROUGHOUT THE FORECAST PERIOD. AS IT TRAVERSES OVER THE VERY WARM WATERS OF THE SOUTH CHINA SEA, IT WILL CONTINUE TO INTENSIFY DESPITE CONTINUED MODERATE TO HIGH (15-25 KTS) VWS TO A MAXIMUM INTENSITY OF 65 KTS BY TAU 36. BETWEEN TAU 36 AND TAU 48 THE SYSTEM WILL MAKE LANDFALL NEAR HUE, VIETNAM AND MAY INTENSIFY SLIGHTLY DURING THIS TIME PRIOR TO REACHING THE COAST. AFTER MAKING LANDFALL JUST AFTER TAU 48, THE SYSTEM WILL BEGIN TO WEAKEN DUE TO INTERACTION WITH THE UNDERLYING TERRAIN. AS TS NOUL DRAGS DEEPER INTO THE INDOCHINA PENINSULA THROUGH LAOS AND INTO THAILAND, IT WILL BEGIN TO DISSIPATE OVER LAND AND WEAKEN TO 35 KTS BY TAU 72. NUMERICAL MODEL SOLUTIONS ARE IN FAIR AGREEMENT FOR THIS INITIAL PORTION OF THE FORECAST PERIOD WITH A 115 NM SPREAD IN ACROSS TRACK SOLUTIONS AT TAU 48 THAT INCREASES TO 218 NM BY TAU 72. THIS FAIR AGREEMENT IN SOLUTIONS LENDS OVERALL FAIR CONFIDENCE TO THE INITIAL PORTION OF THE JTWC FORECAST TRACK. C. AFTER TAU 72, TS NOUL WILL CONTINUE TO DETERIORATE AS IT DRAGS ACROSS THE MOUNTAINOUS TERRAIN OF NORTHERN THAILAND, LEADING TO DISSIPATION AFTER IT CROSSES INTO MYANMAR. NUMERICAL MODEL SOLUTIONS ARE IN FAIR AGREEMENT WITH A MAXIMUM ACROSS TRACK SPREAD OF 358 NM BY TAU 96 NM, AND LEND FAIR CONFIDENCE IN THE OVERALL JTWC FORECAST TRACK WHICH IS PLACED ALONG THE MULTI-MODEL CONSENSUS.// NNNN NNNN