MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 11W (HAISHEN) WARNING NR 016// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON (STY) 11W (HAISHEN), LOCATED APPROXIMATELY 439 NM SOUTHEAST OF KADENA AB, OKINAWA, HAS TRACKED NORTHWESTWARD AT 09 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY REVEALS A WELL-DEFINED, 31 NM ROUND EYE WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. A 040619Z SSMI COMPOSITE MICROWAVE IMAGE DEPICTS A COMPACT EYEWALL (80 NM IN DIAMETER) WITH A DEVELOPING, FRAGMENTED SECONDARY EYEWALL TO THE EAST AND SPIRAL BANDING WRAPPING IN FROM THE SOUTH. THE CIMSS M-PERC PRODUCT INDICATES THAT THERE IS A 60-70% CHANCE THAT STY 11W WILL UNDERGO AN EYEWALL REPLACEMENT CYCLE AS IT PROGRESSES. BASED ON DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM T6.5 (127 KTS) TO T7.0 (140 KTS) AND A 040442Z SATCON ESTIMATE OF 130 KTS, THE INITIAL INTENSITY IS SET AT 135 KTS WITH GOOD CONFIDENCE. TY 11W IS TRANSITING THROUGH A HIGHLY FAVORABLE ENVIRONMENT CHARACTERIZED BY LOW VERTICAL WIND SHEAR (VWS), RADIAL OUTFLOW, WARM (30-31 CELSIUS) SEA SURFACE TEMPERATURES (SST), AND CONDUCIVE OCEAN HEAT CONTENT VALUES. THE 04/0000Z 500MB ANALYSIS SHOWS A DEEP MIDLATITUDE SHORTWAVE TROUGH OVER THE EAST CHINA SEA AND WESTERN JAPAN WITH A BROAD SUBTROPICAL RIDGE (STR) ENTRENCHED NORTH OF THE SYSTEM. ADDITIONALLY, THERE IS A WEAK STR EXTENSION EXTENDING SOUTHWESTWARD FROM THE STR. STY 11W IS TRACKING WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE DEEP-LAYERED STR AND IS TRACKING TOWARD A COL REGION POSITIONED SOUTH OF OKINAWA. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE. B. IN THE NEAR-TERM, THE STR IS FORECAST TO BUILD, REMAINING STATIONARY OVER JAPAN AS THE SHORTWAVE TROUGH GRADUALLY FILLS OVER THE KOREAN PENINSULA. NUMERICAL MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT NEAR OKINAWA WITH A SPREAD OF 42 NM NEAR TAU 36. THE CURRENT FORECAST TRACK REMAINS HIGHLY CONSISTENT WITH THE PREVIOUS FORECAST AND INDICATES A NORTH-NORTHWESTWARD TRACK OVER AMAMI OSHIMA. AT TAU 72, THE SYSTEM IS FORECAST TO TRACK JUST WEST OF KYUSHU. THIS IS SUPPORTED BY THE 04/00Z ECMWF ENSEMBLE; HOWEVER, DUE TO UNCERTAINTY IN THE MODELS AND A 100 NM SPREAD AT TAU 72, THE SYSTEM COULD TRACK CLOSER TO SASEBO / KYUSHU. THROUGH TAU 36, STY 11W IS EXPECTED TO MAINTAIN SUPER TYPHOON INTENSITY. AFTERWARDS, THE SYSTEM WILL GRADUALLY WEAKEN AS IT TRACKS POLEWARD. C. IN THE EXTENDED PERIOD, NUMERICAL MODEL GUIDANCE DIVERGES WITH INCREASING UNCERTAINTY IN THE EXACT TRACK OVER SOUTH KOREA. NAVGEM, A NOTABLE OUTLIER, TRACKS THE SYSTEM FURTHER WEST THAN THE MAJORITY OF THE MODEL SOLUTIONS. AROUND TAU 72, THE SYSTEM IS FORECAST TO BEGIN EXTRATROPICAL TRANSITION (ETT) AS IT INTERACTS WITH THE SHORTWAVE TROUGH. THROUGHOUT THIS TRANSITION, THE SYSTEM WILL ACCELERATE POLEWARD AND SIGNIFICANTLY WEAKEN AS IT TRANSITS OVER THE KOREAN PENINSULA DUE TO INCREASING VWS AND INTERACTION WITH THE MOUNTAINOUS TERRAIN. ETT COMPLETION IS EXPECTED BY TAU 96 AS THE SYSTEM GAINS FRONTAL CHARACTERISTICS AND NEARS THE JET. OVERALL, THERE IS MODERATE CONFIDENCE IN THE JTWC FORECAST TRACK WHICH IS PLACED NEAR THE MULTI- MODEL CONSENSUS.// NNNN NNNN