WDPN31 PGTW 120300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION (TD) 19W/ WARNING NR 01// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 120000Z3 TO 150000Z6 OCT 2003. A. TROPICAL DEPRESSION (TD) 19W, LOCATED APPROXIMATELY 180 NM SOUTH OF SASEBO, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 04 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 112330Z0 MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 25 KNOTS AND SYNOPTIC DATA. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY REVEALS THAT CONVECTION HAS BUILT OVER THE CENTER OF A LOW LEVEL CIRCULATION CENTER THAT WAS PREVIOUSLY A WEAKENING EXTRATROPICAL LOW SUGGESTING THAT THE SYSTEM IS TRANSITIONING TO A WARM CORE, TROPICAL SYSTEM. A RECENT 112108Z3 QUIKSCAT PASS REVEALS THAT THE SYSTEM IS AT WARNING STRENGTH. UPPER LEVEL ANALYSIS SHOWS THAT TD 19W HAS BEEN IN AN AREA OF WEAK VERTICAL SHEAR THOUGH THE LATEST FRAMES HINT THAT THE CONVECTION MAY HAVE BEGUN TO BECOME SHEARED FROM THE WEST. B. TD 19W IS EXPECTED TO TRACK NORTH-NORTHWESTWARDS FOR THE FIRST 12 HOURS ALONG THE WESTERN PERIPHERY OF A LOW TO MID LEVEL STEERING RIDGE ANCHORED TO THE EAST. TD 19W WILL TRANSITION TO A MORE NORTH-NORTHEASTWARD TRACK IN 12 TO 18 HOURS AS A MAJOR SHORTWAVE APPROACHES FROM THE WEST. TD 19W WILL LINK UP WITH THIS SHORTWAVE TROUGH IN 36 TO 48 HOURS AND ACCELERATE RAPIDLY TO THE NORTHEAST AND BEGIN UNDERGOING TRANSITION BACK TO AN EXTRATROPICAL LOW. THE AVAILABLE DYNAMIC AIDS CONSISTING OF NOGAPS, UKMET EGRR, AND NCEP GFS ARE IN FAIR AGREEMENT WITH THIS FORECAST SCENARIO. OUR FORECAST IS BASED ON A CONSENSUS OF THE AVAILABLE DYNAMIC AIDS. C. TD 19W IS EXPECTED TO INTENSIFY ONLY BRIEFLY IN THE TEMPORARY WEAK VERTICAL SHEAR AND WARM TROPICAL WATERS ENHANCED BY THE KIROSHIO CURRENT. TD 19W IS UNLIKELY TO REACH TROPICAL STORM STRENGTH AS IT MAKES LANDFALL IN KYUSHU IN 12 TO 18 HOURS AND INTERACTS WITH THE LAND. TD 19W WILL REMAIN WEAK AS IT SKIRTS THE EASTERN COASTLINE OF JAPAN AND COMPLETES TRANSITION TO AN EXTRATROPICAL LOW BY THE END OF THE FORECAST PERIOD. AN ALTERNATE SOLUTION IS FOR TD 19W TO DISSIPATE COMPLETELY OVER KYUSHU. D. TD 19W DOES NOT MEET CRITERIA FOR WIND RADII. 3. FORECAST TEAM: GRUBER/HEATH/BAK/PACILIO/ANDERSON// NNNN