MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (WUTIP) WARNING NR 13// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 02W (WUTIP), LOCATED APPROXIMATELY 291 NM SOUTH-SOUTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED NORTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM INTENSIFIED SLIGHTLY AS EVIDENCED BY A MORE SYMMETRIC CENTRAL CONVECTION WITH A RAGGED 15-NM FORMATIVE EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE FORMATIVE EYE WITH SLIGHT ADJUSTMENT TO ACCOUNT FOR A POLEWARD TILT AND LINED UP WITH A DEFINED MICROWAVE EYE IN THE 220347Z 36GHZ AMSR2 IMAGE. ANALYSIS INDICATES AN OVERALL FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (15-20 KNOT) VERTICAL WIND SHEAR (VWS) THAT IS OFFSET BY A ROBUST WESTWARD AND POLEWARD DIVERGENT OUTFLOW. SEA SURFACE TEMPERATURES (SSTS) OF 29 CELSIUS ARE ALSO CONDUCIVE. THE CYCLONE IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE NORTH-NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS FORECAST. B. UNDER THE STEERING INFLUENCE OF THE STR, TY 02W IS FORECAST TO CONTINUE TRACKING NORTHWESTWARD THEN, AFTER TAU 48, MORE NORTHWARD AS THE STR RECEDES EASTWARD WITH THE APPROACH OF A MAJOR SHORTWAVE TROUGH FROM THE NORTHWEST. THE SYSTEM WILL PEAK AT 105 KNOTS BY TAU 12 AS THE FAVORABLE ENVIRONMENTAL CONDITIONS PERSIST. AFTERWARD, INCREASING VWS AND COOLING SSTS WILL PRIMARILY BE RESPONSIBLE FOR A SLOW WEAKENING TREND. BY TAU 72, TY 02W WILL BE REDUCED TO 80 KNOTS. NUMERICAL GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU 24 THEN SPREADS OUT TO 245NM BY TAU 72 WITH NAVGEM AND ECMWF SIGNIFICANTLY LEFT OF THE MODEL ENVELOPE. THERE IS OVERALL FAIR CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF THE MULTI-MODEL CONSENSUS TO OFFSET THE LEFT OUTLIERS. C. BEYOND TAU 72, TY WUTIP WILL CONTINUE TRACKING NORTHWARD THEN NORTH-NORTHEASTWARD AS IT ROUNDS THE STR AXIS. INCREASING VWS AND COOLING SSTS WILL CONTINUE TO ERODE THE SYSTEM. THE REDUCED VERTICAL EXTENT WILL RESULT IN A SLOWER STORM MOTION UNDER THE STEERING INFLUENCE OF A LOWER REFLECTION OF THE STR. BY TAU 120, TY 02W WILL WEAKEN TO 45 KNOTS. THERE IS A POSSIBILITY THAT THE SYSTEM WILL ERODE AND WEAKEN AT A FASTER RATE RESULTING IN AN EVEN SLOWER, WESTWARD, OR QUASI-STATIONARY STORM MOTION AFTER TAU 72, AS PROPOSED BY SOME OF THE NUMERICAL MODELS INCLUDING ECMWF, EEMN, AND CTCX. IN VIEW OF THE SIGNIFICANT VARIANCE AMONG THE NUMERICAL MODELS, THERE IS LOW CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC TRACK FORECAST.// NNNN NNNN