WDPN31 PGTW 141500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W (BANYAN) WARNING NR 15// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 14W (BANYAN), LOCATED APPROXIMATELY 343 NM NORTHWEST OF WAKE ISLAND, HAS TRACKED NORTH-NORTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A COMPACT SYSTEM WITH TIGHTLY-CURVED BANDING WRAPPING INTO A FORMATIVE EYE. A 141013Z METOP-A 89GHZ IMAGE SHOWS A MICROWAVE EYE FEATURE, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. ANIMATED WATER VAPOR IMAGERY INDICATES A GRADUALLY IMPROVING UPPER- LEVEL ENVIRONMENT WITH DECREASING NORTHERLY VERTICAL WIND SHEAR (VWS) AND A SLIGHT IMPROVEMENT IN POLEWARD OUTFLOW. THE INITIAL INTENSITY IS ASSESSED AT 80 KNOTS BASED ON DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM 77 TO 90 KNOTS. TY 14W IS TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE EAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 14W WILL CONTINUE TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF THE STR THROUGH TAU 36. UPPER-LEVEL CONDITIONS ARE EXPECTED TO SIGNIFICANTLY IMPROVE OVER THE NEXT 24 TO 30 HOURS AS A SHORTWAVE TROUGH PROPAGATES NORTH OF THE SYSTEM, LEADING TO A PERIOD OF IMPROVED POLEWARD VENTING AND BRIEF PERIOD OF RE-INTENSIFICATION TO A PEAK OF 95 KNOTS AT TAU 24. BEYOND TAU 36, ENVIRONMENTAL CONDITIONS ARE EXPECTED TO GRADUALLY DEGRADE WITH SST VALUES DECREASING BELOW 26C AND MARGINAL OCEAN HEAT CONTENT VALUES. ADDITIONALLY, TY 14W WILL BEGIN TO ACCELERATE NORTH-NORTHEASTWARD TO NORTHEASTWARD AS THE SYSTEM ROUNDS THE NORTHWEST PERIPHERY OF THE STR AND BEGINS EXTRA-TROPICAL TRANSITION (ETT). TY 14W WILL COMPLETE ETT BY TAU 72 AS IT BECOMES FULLY EMBEDDED WITHIN THE MIDLATITUDE WESTERLIES AND GAINS WEAK FRONTAL CHARACTERISTICS. WITH THE EXCEPTION OF NAVGEM AND COAMPS-TC, DYNAMIC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH OVERALL CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN