MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (KUJIRA) WARNING NR 010// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 15W (KUJIRA), LOCATED APPROXIMATELY 734 NM EAST OF YOKOSUKA, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 23 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS STRONG POLEWARD OUTFLOW CONTINUED TO ENHANCE AND DEEPEN THE CENTRAL CONVECTION THAT IS NOW VERY CLOSE TO FORMING AN EYE. THE INITIAL POSITION AND INTENSITY ARE EXTRAPOLATED WITH HIGH CONFIDENCE FROM A DEFINED CIRCULATION IN THE 282328Z ASCAT BULLSEYE PASS AND CLUSTERED DVORAK FIXES OF T3.5/55KTS FROM PGTW AND T4.0/65KTS FROM RJTD. ANALYSIS INDICATES A MARGINALLY-FAVORABLE ENVIRONMENT WITH ROBUST POLEWARD OUTFLOW AND WARM SST (29-30C) THAT ARE PARTLY OFFSET BY LOW TO MODERATE (10-20KT) VERTICAL WIND SHEAR (VWS). ALSO, STRONG CONVERGENCE OVER THE SOUTHERN SEMICIRCLE ASSOCIATED WITH AN UPPER LEVEL TROUGH CONTINUES TO TEMPER CONVECTIVE DEVELOPMENT. TS 15W IS TRACKING UNDER THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE (STR) TO THE EAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS KUJIRA WILL CONTINUE TO ACCELERATE NORTHEASTWARD ON THE POLEWARD SIDE OF THE STR. THE MARGINALLY-FAVORABLE ENVIRONMENT WILL PROMOTE FURTHER INTENSIFICATION TO A PEAK OF 65KTS BY TAU 12. AFTERWARD, INCREASING VWS AND COOLING SSTS WILL GRADUALLY WEAKEN THE SYSTEM TO 45KTS BY TAU 36. CONCURRENTLY BY TAU 12, TS 15W WILL BEGIN EXTRATROPICAL TRANSITION AS IT ENTERS THE BAROCLINIC ZONE, BECOMING A STORM-FORCE COLD CORE LOW BY TAU 24. NUMERICAL MODELS REMAIN IN TIGHT AGREEMENT THROUGHOUT THE FORECAST PERIOD, LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN