MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 15W (KUJIRI) WARNING NR 003// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 15W (KUJIRA), LOCATED APPROXIMATELY 254 NM SOUTHEAST OF MINAMI TORI SHIMA, HAS TRACKED NORTHWESTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH EXTENSIVE DEEP CONVECTIVE BANDING OVER THE SOUTHERN AND EASTERN SEMICIRCLES. A 270729Z SSMIS COMPOSITE MICROWAVE IMAGE INDICATES A BROAD LLCC WITH FRAGMENTED BANDING WRAPPING INTO THE NORTH QUADRANT OF THE SYSTEM. OVERALL, THERE IS FAIR CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY REMAINS ASSESSED AT 30 KNOTS BASED ON PGTW/KNES DVORAK ESTIMATES OF T2.0 (30 KNOTS). UPPER- LEVEL ANALYSIS CONTINUES TO REVEAL A MARGINALLY-FAVORABLE ENVIRONMENT WITH A BROAD, CONVERGENT UPPER LOW POSITIONED OVER THE CENTER, WHICH CONTINUES TO HAMPER DEVELOPMENT, OFFSET BY ROBUST EQUATORWARD OUTFLOW AND DIFFLUENT POLEWARD OUTFLOW. SST VALUES (29C) REMAIN CONDUCIVE FOR FURTHER DEVELOPMENT. TD 15W IS TRACKING NORTHWESTWARD UNDER THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TD 15W IS FORECAST TO TRACK NORTH-NORTHWESTWARD THROUGH TAU 24 WITH STEADY INTENSIFICATION. AFTER TAU 24, TD 15W WILL BEGIN TO ROUND THE STR WITH FURTHER INTENSIFICATION DUE TO IMPROVING POLEWARD OUTFLOW ASSOCIATED WITH A MAJOR SHORTWAVE TROUGH DIGGING SOUTH OF JAPAN. THE SYSTEM IS EXPECTED TO PEAK AT 70 KNOTS BY TAU 48. TD 15W IS FORECAST TO BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT RECURVES INTO THE MIDLATITUDE WESTERLIES NEAR TAU 60. NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGH TAU 72 WITH A SPREAD OF 80NM AT TAU 72. C. AFTER TAU 72, TD 15W WILL WEAKEN AS IT ENCOUNTERS INCREASING VERTICAL WIND SHEAR (30-55 KNOTS) AND TRACKS OVER COOL SST VALUES (22-20C). TD 15W WILL COMPLETE ETT NEAR TAU 84 AS IT GAINS FRONTAL CHARACTERISTICS AND BECOMES EMBEDDED WITHIN THE MIDLATITUDE WESTERLIES. NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGH THE FORECAST PERIOD, LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN