MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (KROSA) WARNING NR 041// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 11W (KROSA), LOCATED APPROXIMATELY 372 NM WEST-SOUTHWEST OF MISAWA, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 19 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM IS CONTINUING TO ERODE AS IT BEGINS TO TRACK INTO THE SEA OF JAPAN (SOJ). THE INITIAL POSITION IS PLACED WITH LOW CONFIDENCE BASED ON A BROAD AND RAGGED LOW LEVEL CIRCULATION (LLC) THAT IS POORLY-DEFINED IN BOTH EIR IMAGERY AND A COMPOSITE REFLECTIVITY RADAR LOOP FROM JMA. THE INITIAL INTENSITY IS BASED ON MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T2.0-2.5 AND A 151229Z METOP-B ASCAT PASS SHOWING 35 KNOT WIND BARBS IN THE NORTHEAST QUADRANT OF THE LLC. UPPER LEVEL ANALYSIS INDICATES LOW (10-15 KNOT) VERTICAL WIND SHEAR (VWS) AND STRONG POLEWARD OUTFLOW. SEA SURFACE TEMPERATURES (SST) ARE BECOMING UNFAVORABLE (26-27 DEGREES CELSIUS). TS 11W IS TRACKING ALONG THE NORTHWESTERN EDGE OF A SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS KROSA IS EXPECTED TO ACCELERATE NORTHEASTWARD ON THE POLEWARD SIDE OF THE STR TOWARD HOKKAIDO. AS TS 11W MOVES OVER COOLER WATERS IN THE SOJ, THE COOLER WATERS WILL INHIBIT FURTHER CONVECTION AND WILL GRADUALLY WEAKEN TS 11W. THE LLC WILL LIKELY RETAIN ITS CURRENT INTENSITY UP TO TAU 12. THE SYSTEM WILL NOW BEGIN EXTRATROPICAL TRANSITION, BECOMING A GALE-FORCE COLD CORE LOW WITH AN EXPANSIVE WIND FIELD BY TAU 24. DYNAMIC MODEL GUIDANCE IS IN TIGHT AGREEMENT, WITH THE EXCEPTION OF AFUM, LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN