MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (GONI) WARNING NR 20// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 16W (GONI), LOCATED APPROXIMATELY 504 NM SOUTH-SOUTHEAST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED WESTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. RECENT ANIMATED ENHANCED INFRARED DEPICTS THE SYSTEM HAS MAINTAINED OVERALL CONVECTIVE SIGNATURE WITH TIGHTLY-CURVED BANDING WRAPPING INTO A 12-NM DIAMETER EYE. THE CURRENT POSITION IS BASED ON THE EYE FEATURE WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 100 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF DVORAK INTENSITY ESTIMATES FROM ALL REPORTING AGENCIES AND THE CURRENT STRUCTURE. UPPER-LEVEL ANALYSIS INDICATES LOW TO MODERATE (10 TO 20 KNOT) VWS AND SUBSIDENCE ALONG THE NORTHERN PERIPHERY THAT ARE OFFSET BY STRONG EQUATORWARD OUTFLOW. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE DEEP STR TO THE NORTH. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 16W WILL CONTINUE TO TRACK GENERALLY WESTWARD THROUGH TAU 48 UNDER THE STEERING INFLUENCE OF THE STR. AFTER TAU 48, AN UPPER- LEVEL TROUGH PASSING TO THE NORTH WILL CAUSE A BREAK IN THE STR, SHIFTING TY 16W POLEWARD. MARGINALLY FAVORABLE CONDITIONS ALONG WITH CONTINUED SUBSIDENCE TO THE NORTH WILL LIMIT THE INTENSIFICATION IN THE SHORT TERM. BY TAU 24, TY 16W IS FORECAST TO TRACK INTO AN IMPROVED ENVIRONMENTAL AND UPPER-LEVEL CONDITIONS, LEADING TO A PEAK INTENSITY OF 115 KNOTS. AFTERWARD, INCREASING VWS AND LOWER OHC VALUES WILL BEGIN TO WEAKEN THE SYSTEM. C. IN THE EXTENDED TAUS, TY 16W WILL CONTINUE TO TRACK POLEWARD DUE TO A BREAK IN THE STR. WEAKENING TREND IS EXPECTED AS DEGRADED CONDITIONS PERSIST. AVAILABLE MODEL GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH TAU 48, BUT CONTINUES TO SHOW A SPREAD IN THE LATER TAUS. DUE TO THE UNCERTAINTY IN THE TIMING OF THE POLEWARD TURN, THE JTWC TRACK FORECAST CONFIDENCE LEVEL REMAINS LOW.// NNNN NNNN