MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (KROSA) WARNING NR 034// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 11W (KROSA), LOCATED APPROXIMATELY 341 NM SOUTH OF IWAKUNI, JAPAN, HAS TRACKED NORTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A BROAD SYSTEM WITH FRAGMENTED, FLARING CONVECTIVE BANDS WRAPPING INTO A LARGE, RAGGED AND FULLY EXPOSED LOW-LEVEL CIRCULATION (LLC). THE INITIAL POSITION IS BASED ON MSI IMAGERY AND A 132216Z SSMIS 89GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY OF 50 KNOTS IS HEDGED SLIGHTLY BELOW THE PGTW AND RJTD DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55 KTS) AND IN CLOSE AGREEMENT WITH A 131105Z SATCON ESTIMATE OF 53 KTS. DESPITE LOW VERTICAL WIND SHEAR (10-15 KNOTS), UPPER LEVEL ANALYSIS INDICATES AN OVERALL MARGINAL ENVIRONMENT WITH AN UPPER LEVEL LOW DIRECTLY OVER THE LLC, WHICH IS INHIBITING CENTRAL CONVECTION. SEA SURFACE TEMPERATURES (SST) REMAIN CONDUCIVE (28-29 DEGREES CELSIUS). THE CYCLONE IS TRACKING ALONG THE WESTERN PERIPHERY OF AN EXTENSION OF THE SUBTROPICAL RIDGE (STR) TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. OVER THE NEXT 24 HOURS, TS 11W WILL CONTINUE ON ITS CURRENT TRACK AS IT ROUNDS THE WESTERN PERIPHERY OF THE AFOREMENTIONED STR. NEAR TAU 24, A MIDLATITUDE TROUGH WILL APPROACH FROM THE WEST, ERODING THE STR AND ALLOWING TS 11W TO RECURVE POLEWARD AROUND THE STR AXIS, SKIRTING WESTERN SHIKOKU JUST AFTER TAU 24. INCREASING POLEWARD OUTFLOW AHEAD OF THE AFOREMENTIONED TROUGH WILL MAINTAIN INTENSITY AT 50 KNOTS AS TS 11W MAKES LANDFALL THROUGH TAU 24. LAND INTERACTION, UNFAVORABLE (20-30 KNOTS) VERTICAL WIND SHEAR (VWS), AND COOLER SST (22-25 DEGREES CELSIUS) IN THE SEA OF JAPAN (SOJ) WILL COMBINE TO WEAKEN THE SYSTEM GRADUALLY DOWN TO 35 KNOTS BY TAU 72 AS IT TRACKS THROUGH THE SOJ. CROSS-TRACK AGREEMENT HAS DECREASED SLIGHTLY, AS THE SPREAD HAS INCREASED TO 300 NM AT TAU 72, WITH UKMET AND NAVGEM SIGNIFICANTLY NORTH AND SOUTH OF THE REMAINING CONSENSUS MODELS. THE JTWC FORECAST TRACK IS IN OVERALL CLOSE AGREEMENT WITH THE MULTI-MODEL CONSENSUS. TS 11W WILL BEGIN EXTRATROPICAL TRANSITION AS IT INTERACTS WITH THE AFOREMENTIONED TROUGH AND IS EXPECTED TO BECOME FULLY EXTRATROPICAL AS IT APPROACHES THE WATERS WEST OF HOKKAIDO NEAR TAU 72. THERE IS OVERALL HIGH CONFIDENCE IN THE JTWC FORECAST TRACK FOR THIS PORTION OF THE FORECAST.// NNNN NNNN