MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (KOPPU) WARNING NR 16// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 24W (KOPPU), LOCATED APPROXIMATELY 237 NM EAST- NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY CONTINUES TO SHOW DEEP CONVECTIVE BANDING WRAPPING TIGHTER INTO THE LOW-LEVEL CIRCULATION CENTER. THE INITIAL POSITION IS BASED ON A WARM PIXEL CLUSTER IN THE EIR LOOP AND ON CLOSELY-GROUPED FIXES FROM ALL AGENCIES WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 95 KNOTS IS HELD SLIGHTLY HIGHER THAN THE DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD TO REFLECT THE TIGHTER WRAP. UPPER-LEVEL ANALYSIS INDICATES THE SYSTEM REMAINS IN A FAVORABLE ENVIRONMENT WITH LOW VERTICAL WIND SHEAR AND DUAL OUTFLOW WITH A STRONG EQUATORWARD BIAS. ADDITIONALLY, SEA SURFACE TEMPERATURES (SSTS) AT OVER 31 DEGREES CELSIUS IN THE PHILIPPINE SEA ARE HIGHLY CONDUCIVE FOR FURTHER DEVELOPMENT. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF AN EXTENSION OF THE DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 24W WILL CONTINUE TO TRACK WESTWARD THROUGH TAU 36 ALONG THE SOUTHERN PERIPHERY OF THE STEERING STR EXTENSION. UPPER-LEVEL DYNAMICS AND SSTS WILL REMAIN FAVORABLE LEADING TO A RAPID INTENSIFICATION OVER THE NEXT 24 HOURS WITH A PEAK INTENSITY OF 120 KNOTS NEAR TAU 18. THE CYCLONE WILL MAKE LANDFALL SHORTLY AFTER TAU 24 NEAR CASIGURAN AND RAPIDLY DECAY AS IT TRACKS THROUGH NORTHERN LUZON. BEYOND TAU 36, TY 24W WILL TURN POLEWARD AS THE STR EXTENSION RETREATS AND AN INDUCED RIDGE FORMS BETWEEN TY 25W AND TY 24W AND ACTS AS THE WEAK PRIMARY STEERING MECHANISM FOR THE REMAINDER OF THE FORECAST. C. IN THE EXTENDED FORECAST, TY KOPPU WILL EXIT INTO THE LUZON STRAIT AT TROPICAL STORM STRENGTH AND CONTINUE TO TRACK NORTHWARD. MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGH TAU 36, BUT CONTINUES TO SHOW SIGNIFICANT SPREAD AFTERWARDS. DUE TO THE UNCERTAINTY IN THE STORM MOTION AND DISPARITY AMONG AVAILABLE TRACKERS IN THE EXTENDED TAUS, THE JTWC TRACK FORECAST CONFIDENCE LEVEL IS LOW.// NNNN NNNN