MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 11W (HAISHEN) WARNING NR 018// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON (STY) 11W (HAISHEN), LOCATED APPROXIMATELY 329 NM SOUTHEAST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWESTWARD AT 09 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED A WELL-DEFINED 22-NM ROUND EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE, ADJUSTED FOR A VERY SLIGHT SOUTHWESTWARD TILT. THE INITIAL INTENSITY OF 135 KTS IS BASED ON THE HIGH END OF MULTI-AGENCY DVORAK ESTIMATES RANGING FROM T6.5 (127 KTS) TO T7.0 (140 KTS) AND REFLECTS THE SUSTAINED HIGHLY SYMMETRIC AND COMPACT EIR STRUCTURE. STY 11W IS IN AN OVERALL FAVORABLE ENVIRONMENT WITH LOW (05-10KT) NORTHEASTERLY VERTICAL WIND SHEAR (VWS), EXCELLENT RADIAL OUTFLOW, AND WARM (30-31C) SEA SURFACE TEMPERATURES (SST). THE CYCLONE IS TRACKING UNDER THE STEERING INFLUENCE OF THE DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTHEAST, SITTING EAST OF HOKKAIDO JAPAN. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE. B. STY 11W WILL CONTINUE ON ITS CURRENT TRACK UNDER THE STEERING STR. AROUND TAU 24, A SHORTWAVE TROUGH APPROACHING FROM THE NORTHWEST WILL WEAKEN THE STR AND ALLOW THE SYSTEM TO TRACK MORE POLEWARD, PASS JUST TO THE WEST OF KYUSHU, JAPAN, ACROSS THE KOREA STRAIT, MAKE LANDFALL JUST WEST OF BUSAN, SOUTH KOREA BEFORE TAU 60, THEN DRAG NORTHWARD ALONG THE RUGGED MOUNTAIN RANGES OF THE KOREAN PENINSULA. INCREASING VWS, COOLING SSTS, AND EVENTUALLY, LAND INTERACTION WILL GRADUALLY, THEN RAPIDLY ERODE THE SYSTEM, AND BY TAU 72 WILL BE REDUCED TO 45 KTS AFTER IT CROSSES INTO NORTH KOREA. CONCURRENTLY, THE CYCLONE WILL BEGIN EXTRA-TROPICAL TRANSITION AROUND TAU 48 AS IT ENTERS THE BAROCLINIC ZONE AND TRANSFORM INTO A STORM-FORCE COLD CORE LOW BY TAU 72. C. BEYOND TAU 72, STY HAISHEN WILL CONTINUE NORTHWARD AND CROSS INTO MANCHURIA AND BY TAU 96, REDUCED TO A WEAK 25-KT EXTRA-TROPICAL LOW. NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH ECMWF AND JGSM OUTLYING ON THE RIGHT OF THE MODEL ENVELOPE AFTER TAU 36. THERE IS OVERALL HIGH CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID JUST LEFT OF THE MULTI-MODEL CONSENSUS BEYOND TAU 36 TO OFFSET THE OUTLIERS.// NNNN NNNN