MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 01W (VONGFONG) WARNING NR 011// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 01W (VONGFONG), LOCATED APPROXIMATELY 289 NM EAST- SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTI-SPECTRAL VISIBLE SATELLITE IMAGERY SHOWS A TIGHT CLOUD FILLED 8NM EYE. TY 01W IS CURRENTLY LOCATED OVER EASTERN SAMAR. A 140531Z GMI 89GHZ MICROWAVE PASS REVEALED A LARGE SWATH OF DEEP CONVECTION AROUND THE EASTERN SEMI- CIRCLE, WHILE THE CORE CONVECTION ALONG THE WESTERN SIDE OF THE MICROWAVE EYE WAS DEGRADED. THE INITIAL INTENSITY IS SET AT 100 KNOTS BASED ON A T5.5 (102 KNOTS) FROM RJTD AND A 140459Z SATCON ESTIMATE OF 103 KNOTS. THE INITIAL POSITION WAS PLACED WITH HIGH CONFIDENCE BASED ON EYE FIXES AND THE AFOREMENTIONED MICROWAVE IMAGE. THE ENVIRONMENT REMAINS FAVORABLE WITH ROBUST RADIAL OUTFLOW AND WARM SSTS PARTIALLY OFFSETTING MID-LEVEL DRY AIR. TY 01W IS BEING STEERED BY A DEEP-LAYER SUBTROPICAL RIDGE (STR) POSITIONED NORTHEAST OF LUZON WHICH IS EXTENDING WEST TOWARD THE LUZON STRAIT. 3. FORECAST REASONING. A. THERE HAS BEEN NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY. B. TY 01W IS EXPECTED TO GRADUALLY SHIFT TO A NORTHWEST AND THEN NORTHWARD TRACK OVER THE NEXT 12-36 HOURS AS IT ROUNDS THE AFOREMENTIONED STR. THE TRACK FOLLOWS ALONGSIDE THE MULTI-MODEL CONSENSUS SOLUTION. AFTER TAU 48, TY 01W SHOULD COMPLETE ROUNDING THE STR AXIS. A CONTINUOUS WEAKENING TREND IS FORECAST AS TY 01W TRAVELS OVER ACROSS THE PHILIPPINES AS FAVORABLE CONDITIONS OFFSET THE FRICTIONAL EFFECTS OF THE ISLANDS. A MORE PRONOUNCED WEAKENING TREND IS EXPECTED AS THE SYSTEM TRACKS OVER LUZON. DUE TO UNCERTAINTY OF WHEN THE NORTHWARD TURN WILL OCCUR, OVERALL CONFIDENCE IS FAIR FOR THIS PORTION OF THE FORECAST WITH A CROSS TRACK SPREAD OF 140NM AT TAU 48. C. AFTER TAU 72, TY 01W WILL COMPLETE RECURVATURE AND BEGIN A NORTHEASTWARD TRACK AFTER ENTERING THE LUZON STRAIT. INCREASING VWS (25-30 KNOTS) AS TY 01W NEARS A BAROCLINIC ZONE, ALONG WITH COOLING SSTS WILL LEAD TO FURTHER WEAKENING OF THE SYSTEM TO 35 KTS BY TAU 96. AT TAU 72, INTERACTION WITH STRONG UPPER LEVEL WESTERLY FLOW WILL CAUSE THE SYSTEM TO BEGIN EXTRATROPICAL TRANSITION, WITH COMPLETE EXTRATROPICAL TRANSITION COMPLETE BY TAU 120 AS IT IS FULLY ABSORBED INTO THE BAROCLINIC ZONE. THERE IS SIGNIFICANT ALONG TRACK SPREAD OF MODEL SOLUTIONS AFTER TAU 72. THE LARGE SPREAD IN MODEL GUIDANCE LENDS HIGH UNCERTAINTY DURING THIS PERIOD AND THUS LOW CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK.// NNNN NNNN