WDPN31 PGTW 232100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 02W (WUTIP) WARNING NR 19// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON 02W (WUTIP), LOCATED APPROXIMATELY 142 NM WEST- SOUTHWEST OF NAVSTA GUAM, HAS TRACKED NORTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A WELL-DEFINED BUT ERODING EYEWALL, PARTICULARLY ON THE WESTERN SIDE, AS WELL AS WARMING CLOUD TOPS AND A COOLING EYE. A 231431Z GMI 89GHZ IMAGE REVEALS WHAT APPEARS TO BE DOUBLE EYEWALLS, AND IT IS SUSPECTED THAT STY 02W IS UNDERGOING AN EYEWALL REPLACEMENT CYCLE (ERC). THE INITIAL POSITION IS BASED ON RADAR IMAGERY AND THE EYE IN EIR IMAGERY WITH HIGH CONFIDENCE. AFTER RAPIDLY INTENSIFYING FOR A 24-HOUR PERIOD, STY 02W HAS MAINTAINED THE 135-KT INTENSITY WHILE IT UNDERGOES THE ERC. THE CURRENT INTENSITY IS BETWEEN THE RANGE OF MULTIAGENCY DVORAK CURRENT INTENSITY ESTIMATES FROM T6.5 (127 KTS) TO T7.0 (140 KTS), AND AGREES WITH A 241604Z SATCON ESTIMATE OF 136 KTS. OBSERVATIONS FROM ANDERSEN AFB ON GUAM SHOW WINDS HAVE SLACKENED, WITH GUSTS BETWEEN 30-40 KTS AS CONVECTIVE RAINBANDS MOVE OVER THE AREA, AND SUSTAINED WINDS WEAKENING FROM 28 KTS TO 22 KTS OVER THE PAST 6 HOURS. UPPER- LEVEL CONDITIONS REMAIN FAVORABLE WITH LOW TO MODERATE (10 TO 20 KNOTS) SOUTHEASTERLY VERTICAL WIND SHEAR (VWS) OFFSET BY A ROBUST POLEWARD OUTFLOW CHANNEL AND GOOD EQUATORWARD OUTFLOW. SST VALUES HAVE DECREASED TO 27C BUT REMAIN FAVORABLE. STY 02W IS TRACKING NORTHWESTWARD UNDER THE STEERING INFLUENCE OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. STY 02W SHOULD CONTINUE TO TRACK NORTHWESTWARD TO NORTHWARD UNDER THE STEERING INFLUENCE OF THE AFOREMENTIONED STR TO THE NORTHEAST THROUGH TAU 72. AFTER TAU 24, THE STR WILL ERODE SOMEWHAT, ALLOWING FOR A MORE NORTHWARD TRACK. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT IN THE NEAR-TERM, WITH A 168NM SPREAD IN THE MODEL SOLUTIONS AT TAU 72. THE GALWEM AND UKMET MODEL SOLUTION ARE FURTHER EAST AND SHOW A MORE NORTH-NORTHWESTWARD TRACK THAN DO THE OTHER MODELS, WHILE ECMWF, HWRF, NAVGEM, AND GFS ARE IN LINE WITH OR SLIGHTLY WEST OF THE MULTI-MODEL CONSENSUS. IN GENERAL, THERE IS SOME UNCERTAINTY IN THE INTENSITY FORECAST DUE TO MODEL DIFFICULTY IN RESOLVING INTERNAL PROCESSES IN TROPICAL CYCLONES. HOWEVER, THE SYSTEM IS EXPECTED TO MAINTAIN AT STY STRENGTH THROUGH TAU 24 DUE TO THE STRONG POLEWARD OUTFLOW. SLIGHT ADDITIONAL INTENSIFICATION TO 140 KTS IS POSSIBLE BY TAU 12 AFTER STY 02W COMPLETES THE ONGOING ERC AND THE NEW PRIMARY EYEWALL CONTRACTS. AFTER TAU 24, STY 02W WILL WEAKEN STEADILY AS OUTFLOW DIMINISHES. C. AFTER TAU 72, INCREASING VWS (20 TO 40 KNOTS) AND CONVERGENCE ASSOCIATED WITH A SHORTWAVE TROUGH WILL RAPIDLY WEAKEN THE SYSTEM. THE WEAKENED SYSTEM WILL ACCELERATE WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF A STRONG LOW-LEVEL RIDGE AND NORTHEASTERLY SURGE FORECAST TO BUILD SOUTH AND SOUTHEAST OF JAPAN. DUE TO THE COMPLEX AND RAPIDLY EVOLVING SYNOPTIC PATTERN, THERE IS INCREASING UNCERTAINTY IN THE EXACT TRACK WITH A 485NM SPREAD IN SOLUTIONS AT TAU 120. NAVGEM AND THE GFS ENSEMBLE ARE THE NORTHEASTERN OUTLIERS AND SHOW A MORE PRONOUNCED KINK TO THE NORTH BEFORE TURNING THE TRACK WESTWARD THAN DO THE OTHER MODELS AND THE MULTI-MODEL CONSENSUS. NAVGEM MAINTAINS AN UNREALISTICALLY HIGH INTENSITY THROUGHOUT THE FORECAST PERIOD DESPITE THE ENVIRONMENT BECOMING UNFAVORABLE, THUS SUBJECTING ITS MODEL TRACKER TO STEERING INFLUENCES DEEPER IN THE ATMOSPHERE AND ALLOWING THE MORE NORTHWARD TRACK AT LATER TAUS. ECMWF, GFS, AND HWRF DIVERGE TO THE SOUTHWEST OF THE MULTI-MODEL CONSENSUS, MORE REALISTICALLY REPRESENTING THE INFLUENCE OF LOW-LEVEL NORTHEASTERLY SURGE ON A WEAKENED SYSTEM. STY 02W IS FORECAST TO WEAKEN MORE RAPIDLY IN LATER TAUS THAN PREVIOUSLY DUE TO DRY, COLD AIR ASSOCIATED WITH THE NORTHEASTERLY COLD SURGE, COOLER SSTS, AND THE LOSS OF FAVORABLE POLEWARD OUTFLOW. THE JTWC FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH LOW CONFIDENCE.// NNNN