WDPN31 PGTW 150300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (MAN-YI) WARNING NR 10// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 16W (MAN-YI), LOCATED APPROXIMATELY 484 NM SOUTHWEST OF YOKOSUKA, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A WELL DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTIVE BANDING TO THE NORTH AND SOUTH OF THE SYSTEM WHICH WRAP AROUND THE PERIPHERIES OF TS 16W INTO THE LLCC. A 142246Z 89GHZ SSMIS MICROWAVE IMAGE REVEALS THE FRAGMENTED STRUCTURE OF THE AFOREMENTIONED BANDING FEATURES, BUT DOES INDICATE AN OVERALL IMPROVEMENT OVER THE PAST SIX HOURS. ADDITIONALLY, A 142142Z 37GHZ WINDSAT MICROWAVE IMAGE REVEALS AN IMPROVED LOW-LEVEL STRUCTURE WITH NUMEROUS CONVECTIVE BANDING FEATURES AS WELL AS INDICATES THAT TS 16W IS A LARGE SYSTEM WITH A DIAMETER OF APPROXIMATELY 540 NM. THE INITIAL POSITION IS BASED ON THE MSI AND THE AFOREMENTIONED MICROWAVE IMAGES WITH HIGH CONFIDENCE. THE LARGE DIAMETER OF THE SYSTEM REVEALED IN THE WINDSAT IMAGE CONTINUES TO INDICATE EXPANSIVE GALE-FORCE WINDS, EASILY SUPPORTING THE INITIAL 34-KNOT WIND RADII ESTIMATES OF 120 TO 135 NM THAT WAS DEPICTED IN THE PREVIOUSLY DISCUSSED 141143Z ASCAT AND A 141408Z OSCAT IMAGES. THE INITIAL INTENSITY IS ASSESSED AT 50 KNOTS BASED ON THE MAINTAINED, IF NOT IMPROVED, STRUCTURE OF THE SYSTEM AS WELL AS DVORAK ESTIMATES OF 45 KNOTS FROM PGTW, RJTD, AND KNES. SATCON INDICATES AN INTENSITY OF 54 KNOTS WHILE 15/00Z SURFACE ANALYSIS FROM JMA AND KMA INDICATE 50 AND 60 KNOTS, RESPECTIVELY. UPPER-LEVEL ANALYSIS INDICATES TS 16W IS BEGINNING TO EXPERIENCE INCREASED POLEWARD OUTFLOW AS THE NORTHERN PERIPHERIES OF THE SYSTEM HAVE BEGUN INTERACTING WITH THE APPROACHING MIDLATITUDE SHORTWAVE TROUGH AND MIDLATITUDE WESTERLY FLOW. VERTICAL WIND SHEAR REMAINS AT 10 TO 20 KNOTS, BUT IS EXPECTED TO INCREASE AS THE TROUGH AND TS 16W MOVE CLOSER TO ONE ANOTHER. THE EQUATORWARD OUTFLOW CONTINUES TO BE RESTRICTED OVER THE SOUTHERN SEMI-CIRCLE DUE TO A NARROW BAND OF CONVERGENT FLOW ASSOCIATED WITH A TIGHT UPPER-LEVEL TROUGH. TS 16W IS TRACKING NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 16W IS FORECAST TO TURN NORTHEASTWARD BY TAU 12 AS IT TRACKS ALONG THE WESTERN PERIPHERY OF THE STR. AFTER TAU 12, TS 16W WILL ACCELERATE AS IT BEGINS TO FULLY INTERACT WITH THE APPROACHING MIDLATITUDE SHORTWAVE TROUGH. EXTRA-TROPICAL TRANSITION (ETT) IS FORECAST TO BEGIN NEAR TAU 24 AND THE SYSTEM SHOULD COMPLETE ETT BY TAU 36. MODEL GUIDANCE INDICATES THAT THE SYSTEM WILL BECOME EMBEDDED WITHIN THE MIDLATITUDE WESTERLIES NEAR THE KANTO PLAIN WITH A FRONTAL SIGNATURE SHOWN IN THE 1000-500MB THICKNESS FIELDS. DYNAMIC MODEL GUIDANCE INDICATES A SLIGHT WESTWARD SHIFT AFTER TAU 24 IN THE JTWC MULTI-MODEL CONSENSUS TRACK. DESPITE THIS SUBTLE SHIFT, DYNAMIC GUIDANCE REMAINS IN TIGHT AGREEMENT, WITH THE EXCEPTION OF GFDN AND NAVGEM, WHICH HAVE REMAINED HIGHLY ERRATIC AND ARE DISCOUNTED FROM THE ANALYSIS. OVERALL, THERE IS HIGH CONFIDENCE IN THE TRACK SCENARIO AND THE JTWC FORECAST TRACK BASED ON THE STRONG AGREEMENT OF THE DYNAMIC GUIDANCE. THE JTWC TRACK IS POSITIONED SLIGHTLY FASTER THAN THE MULTI-MODEL CONSENSUS TO OFFSET THE TWO OUTLIERS. THE INTENSITY FORECAST REMAINS CHALLENGING DUE TO THE LARGE SIZE OF THE SYSTEM AND WEAK CORE CONVECTION. THE PEAK INTENSITY REMAINS SET AT 60 KNOTS AT TAU 12 WITH A WEAKENING TREND EXPECTED AS TS 16W APPROACHES JAPAN AND THE KANTO PLAIN DUE TO INCREASING VWS AND LAND INTERACTION. THE SYSTEM IS EXPECTED TO MAINTAIN 50 TO 55 KNOT SUSTAINED WINDS AS IT TRACKS ACROSS THE KANTO PLAIN AND SHOULD ALSO MAINTAIN EXPANSIVE GALE FORCE WINDS AS IT TRACKS BACK OVER WATER. THE INTENSITY FORECAST IS HEDGED SLIGHTLY HIGHER THAN THE STIPS GUIDANCE, WHICH PEAKS NEAR 54 KNOTS BETWEEN TAU 12 AND 24.// NNNN