MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 27W (SAOLA) WARNING NR 39// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 27W (SAOLA), LOCATED APPROXIMATELY 211 NM EAST- SOUTHEAST OF IWAKUNI, JAPAN, HAS TRACKED EAST-NORTHEASTWARD AT 28 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS TS SAOLA IS RAPIDLY DECAYING AND THE CONVECTION HAS BEEN DISPLACED TO THE NORTHEAST AS IT BECOMES EMBEDDED IN THE MID-LATITUDE WESTERLIES. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE MULTISPECTRAL LOOP AND ANIMATED RADAR LOOPS FROM JMA. THE INITIAL INTENSITY OF 60 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF MULTIAGENCY DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM T3.5 TO T4.5 (55-77 KNOTS) AND IS SUPPORTED BY A SATCON ESTIMATE OF 61 KNOTS. ENVIRONMENTAL ANALYSIS REVEALS THAT THE SYSTEM IS IN AN AREA OF STRONG (30+ KNOT) VERTICAL WIND SHEAR AND IS TRACKING THROUGH AN AREA OF COOL (<26 CELSIUS) SEA SURFACE TEMPERATURES. DRY AIR ADVECTION CONTINUES TO BE EVIDENT IN BOTH THE TOTAL PRECIPITABLE WATER LOOP, AND BY THE ENTRAINMENT OF STRATOCUMULUS CLOUD LINES FROM THE NORTHWEST ON THE MULTISPECTRAL LOOP. TS SAOLA IS ACCELERATING NORTHEASTWARD ALONG THE NORTHWESTERN EXTENT OF A DEEP-LAYERED SUBTROPICAL RIDGE TO THE SOUTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS SAOLA IS FORECAST TO CONTINUE ACCELERATING NORTHEASTWARD, TRACKING ALONG THE SOUTHERN COAST OF JAPAN. THE SYSTEM WILL PASS JUST SOUTH OF TOKYO MAKING A VERY BRIEF LANDFALL. THE UNFAVORABLE ENVIRONMENT WILL CAUSE THE SYSTEM TO GRADUALLY WEAKEN THROUGHOUT THE FORECAST PERIOD. THE SYSTEM HAS EMBEDDED IN THE MID-LATITUDE BAROCLINIC ZONE AND BEGUN EXTRA-TROPICAL TRANSITION. TS 27W WILL COMPLETE EXTRA-TROPICAL TRANSITION BY TAU 12, BECOMING A GALE-FORCE COLD CORE LOW WITH AN EXPANSIVE WIND FIELD. AVAILABLE DYNAMIC MODEL GUIDANCE IS IN STRONG AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST.// NNNN NNNN