WDPN34 PGTW 231500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (WUKONG) WARNING NR 08// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 14W (WUKONG), LOCATED APPROXIMATELY 337 NM NORTHEAST OF MINAMI TORI SHIMA, HAS TRACKED NORTHWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED SHORTWAVE INFRARED (SWIR) SATELLITE IMAGERY SHOWS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION (LLC) TUCKING UNDER A LARGE CENTRAL DENSE OVERCAST (CDO) REGION WITH CONVECTIVE BANDING EXTENDING 450 NM EASTWARD IN THE SHAPE OF A COMMA- CLOUD. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE SWIR LOOP AND EXTRAPOLATION OF A 230910Z MHS 89GHZ MICROWAVE IMAGE REVEALING A MOSTLY EXPOSED LLCC WITH DEEP CONVECTIVE BANDING WRAPPING OVER THE NORTHERN SEMI-CIRCLE. THE INITIAL INTENSITY OF 45 KNOTS IS HEDGED TO THE HIGH END OF MULTI-AGENCY DVORAK ESTIMATES RANGING T2.5 TO T3.0 (35-45 KNOTS) BASED ON A PARTIAL 231111Z METOP-B ASCAT PASS SHOWING 45KTS IN THE NORTHWESTERN QUADRANT. UPPER LEVEL ANALYSIS SHOWS THAT TS 14W HAS AN EXCELLENT OUTFLOW CHANNEL WHICH IS ENHANCED BY A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) CELL TO THE SOUTHWEST OF THE LLCC. THE SYSTEM IS IN AN AREA OF MARGINALLY FAVORABLE (10-20 KNOTS) SOUTHWESTERLY VERTICAL WIND SHEAR (VWS) WHICH HAS DECREASED SIGNIFICANTLY OVER THE LAST 18 HOURS AS THE SYSTEM HAS PASSED NORTH OF THE AFOREMENTIONED TUTT CELL. THIS TUTT CELL HAD PREVIOUSLY BEEN CAUSING HIGH VWS AND CAUSING THE SYSTEM TO EXHIBIT SUBTROPICAL CHARACTERISTICS, NAMELY AN EXPANSIVE WIND FIELD WITH THE STRONGEST WINDS LOCATED 100NM EAST OF THE LLCC. SEA SURFACE TEMPERATURES IN THE AREA REMAIN FAVORABLE (27-28 CELSIUS) FOR ADDITIONAL INTENSIFICATION. TS 14W IS TRACKING NORTH ALONG THE SOUTHWESTERN EXTENT OF AN EXTENSION OF A SUB-TROPICAL RIDGE (STR) LOCATED TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 14W IS FORECAST TO INITIALLY TRACK NORTH-NORTHWESTWARD THROUGH TAU 24 AT WHICH TIME THE TRACK BEGINS TO SHIFT MORE NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR TO THE NORTHEAST. THE SYSTEM IS FORECAST TO GRADUALLY INTENSIFY AS IT MOVES NORTH OF THE TUTT CELL TO THE WEST, CAUSING VWS TO FURTHER DECREASE. ALONG TRACK SEA SURFACE TEMPERATURES (SSTS) REMAIN FAVORABLE (27-28 CELSIUS) AND 14W IS EXPECTED TO MAINTAIN GOOD OUTFLOW THROUGH TAU 36. THIS GRADUAL INTENSIFICATION WILL LEAD TO A PEAK OF 65 KNOTS AROUND TAU 36. TS 14W IS EXPECTED TO MAINTAIN THIS INTENSITY THROUGH TAU 48, AS VWS INCREASES SLIGHTLY AND SSTS DROP TO A MARGINALLY FAVORABLE 26 CELSIUS. AFTER TAU 48, THE SYSTEM WILL BEGIN A STEADY WEAKENING TREND, THE RESULT OF INCREASING VERTICAL WIND SHEAR DUE TO AN APPROACHING MID-LATITUDE TROUGH. ADDITIONALLY, BY TAU 48 THE SYSTEM WILL BE NORTH OF 35 DEGREES LATITUDE, WHERE SEA SURFACE TEMPERATURES DROP OFF RAPIDLY, CONTRIBUTING TO THE WEAKENING TREND. THE SYSTEM IS FORECAST TO BEGIN EXTRA-TROPICAL TRANSITION (ETT) BY TAU 48 AND COMPLETE ETT BY TAU 72. DYNAMIC MODEL GUIDANCE REMAINS IN STRONG AGREEMENT THROUGH TAU 72. DESPITE SOME UNCERTAINTY IN INITIAL POSITION, THERE IS HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN