MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (FRANCISCO) WARNING NR 21// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 09W (FRANCISCO), LOCATED APPROXIMATELY 102 NM NORTH OF PUSAN, SOUTH KOREA, HAS TRACKED NORTHWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 061715Z ATMS 88.2GHZ IMAGE DEPICT A RAPIDLY DECAYING SYSTEM WITH DEEP CONVECTION SHEARED NORTH OF A BROAD LOW-LEVEL CIRCULATION CENTER (LLCC). RADAR IMAGERY INDICATES A DEFINED LLCC WITH CONVECTIVE BANDING WRAPPING INTO THE CENTER, WHICH SUPPORTS THE INITIAL POSITION WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 40 KNOTS, HEDGED ABOVE THE RCTP/RJTD DVORAK INTENSITY ESTIMATES OF T2.5 (35 KNOTS), BASED ON THE CONVECTIVE STRUCTURE. TS 09W IS LOCATED UNDER THE LEADING EDGE OF A SHARP UPPER-LEVEL SHORTWAVE TROUGH AND IS UNDER SOUTHERLY VERTICAL WIND SHEAR (VWS). THE SYSTEM IS TRACKING UNDER THE INFLUENCE OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 09W IS FORECAST TO RECURVE NORTHEASTWARD TO EASTWARD OVER THE NEXT 36 TO 48 HOURS WHILE UNDERGOING EXTRA-TROPICAL TRANSITION (ETT). GRADUAL WEAKENING IS EXPECTED AS THE SYSTEM BECOMES EMBEDDED IN THE MIDLATITUDE WESTERLIES AND ENCOUNTERS INCREASING VWS AND COOLER SST. TS 09W SHOULD COMPLETE ETT BY TAU 36 AS IT GAINS FRONTAL CHARACTERISTICS BUT IS FORECAST TO MAINTAIN GALE-FORCE WINDS. NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN