MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 10W (LEKIMA) WARNING NR 14// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 10W (LEKIMA), LOCATED APPROXIMATELY 336 NM SOUTH OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS DEVELOPED A WELL-DEFINED 10-NM EYE AS IT BECAME MORE COMPACT AND CONSOLIDATED. THE SYSTEM STILL TRAILS A LARGE RAIN BAND TO THE SOUTHWEST. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE THAT LINED UP PERFECTLY WITH A SHARPLY OUTLINED MICROWAVE EYE IN THE 070453Z 36GHZ AMSR2 IMAGE. THE INITIAL INTENSITY OF 85 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF TIGHTLY CLUSTERED AGENCY DVORAK FIXES RANGING FROM T4.5/77KTS TO T5.0/90KTS. ENVIRONMENTAL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH NEAR-RADIAL OUTFLOW, LOW VERTICAL WIND SHEAR AND WARM SST (30C). TY 10W IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 10W WILL CONTINUE ON ITS CURRENT NORTHWESTWARD TRACK UNDER THE INFLUENCE OF THE STR, PASSING JUST TO THE NORTH OF TAIWAN NEAR TAU 48 BEFORE TURNING MORE POLEWARD. THE FAVORABLE CONDITIONS WILL FUEL GRADUAL TO RAPID INTENSIFICATION TO A PEAK OF 125 KNOTS BY TAU 48. AFTERWARD, INCREASING VWS AND LAND INTERACTION WILL WEAKEN IT TO 100 KNOTS BY TAU 72 AS IT APPROACHES THE CHINESE COAST. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A 155NM SPREAD IN SOLUTIONS AT TAU 48 NEAR TAIWAN, LENDING FAIR CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK. C. AFTER TAU 72, TY 10W WILL TURN NORTHWARD AS THE STR REORIENTS IN A NORTH-SOUTH CONFIGURATION TO THE EAST. STEADY WEAKENING IS EXPECTED PRIMARILY DUE TO INCREASING VWS AND LAND INTERACTION AS THE SYSTEM STRADDLES THE EASTERN CHINESE COAST. BY TAU 120, TY 10W WILL BE REDUCED TO 60 KNOTS AFTER IT PASSES JUST TO THE EAST OF SHANGHAI. NUMERICAL MODELS SIGNIFICANTLY DIVERGE WITH AFUM ON THE LEFT AND NAVGEM ON THE RIGHT MARGIN OF THE ENVELOPE, SPANNING A SWATH OF OVER 650NM. THEREFORE, THERE IS LOW CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC FORECAST TRACK THAT IS LAID TO THE LEFT OF CONSENSUS TO OFFSET THE UNLIKELY NAVGEM SOLUTION DRIVING THE CYCLONE STRAIGHT INTO THE STR. SINCE THE EVENTUAL TRACK AFFECTS THE PROJECTED INTENSITY, THERE IS ALSO LOW CONFIDENCE IN THE INTENSITY FORECAST AT THE EXTENDED TAUS.// NNNN NNNN