MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (HALONG) WARNING NR 06// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 11W (HALONG), LOCATED APPROXIMATELY 76 NM EAST OF ANDERSEN AFB, GUAM HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS IMPROVED CONVECTIVE BANDING ASSOCIATED WITH A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). A 291612Z NOAA-19 IMAGE ALSO REVEALS TIGHTLY-CURVED BANDING WRAPPING INTO THE LLCC. THE CURRENT POSITION IS SUPPORTED BY THE ABOVE MICROWAVE IMAGE AND RADAR FIXES WITH GOOD CONFIDENCE. THE INITIAL INTENSITY OF 55 KNOTS IS BASED ON CONVECTIVE STRUCTURE AND CONSISTENT DVORAK INTENSITY ESTIMATES KNOTS FROM PGTW AND KNES. UPPER-LEVEL ANALYSIS INDICATES ENHANCED OUTFLOW PROVIDED BY A TUTT CELL TO THE NORTHEAST. ADDITIONALLY, EXCELLENT EQUATORWARD OUTFLOW HAS PERSISTED SUSTAINING THE DEEP CONVECTION. TS 11W IS TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE NORTH. 3. FORECAST REASONING. A. NO SIGNIFICANT CHANGES TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING. B. TS 11W IS EXPECTED TO TRACK WESTWARD TO WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR THROUGH TAU 36. AFTER TAU 36, THE STR SHOULD MAINTAIN A NORTHWEST-SOUTHEAST ORIENTATION, WHICH WILL SHIFT TS HALONG NORTHWESTWARD THROUGH TAU 72. IN ADDITION TO FAVORABLE SEA SURFACE TEMPERATURES, UPPER-LEVEL CONDITIONS ARE EXPECTED TO IMPROVE, ALLOWING TS 11W TO FURTHER INTENSIFY AND LEADING TO A PEAK INTENSITY OF 105 KNOTS AT TAU 72. C. TS HALONG IS EXPECTED TO WEAKEN BY TAU 96 AS THE SYSTEM ENCOUNTERS INCREASING VERTICAL WIND SHEAR ASSOCIATED WITH UPPER- LEVEL NORTHERLY FLOW ALONG THE EASTERN FLANK OF THE UPPER-LEVEL HIGH. AVAILABLE MODEL GUIDANCE IS IN GOOD AGREEMENT; HOWEVER, DUE TO THE INCREASED UNCERTAINTY IN THE TRACK AND INTENSITY FORECAST AT THE EXTENDED TAUS, THERE IS OVERALL LOW CONFIDENCE IN THE JTWC FORECAST.// NNNN NNNN