UNCLAS //N03145// MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W WARNING NR 03// RMKS/ WDPN31 PGTW 010300 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 010000Z1 TO 040000Z4 JUN 03. A. TROPICAL DEPRESSION (TD) 06W, LOCATED APPROXIMATELY 185 NM WEST OF NORTHERN LUZON, PHILIPPINES, HAS DRIFTED NORTHEASTWARD AT 01 KNOT OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 312330Z2 MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 25 TO 35 KNOTS. ANIMATED MULTISPECTRAL AND ENHANCED INFRARED SATELLITE IMAGERY REVEAL THAT THE DEEP CONVECTION IS PRIMARILY TO THE SOUTH OF THE SYSTEM. ANIMATED WATER VAPOR SATELLITE IMAGERY AND THE RECENT MICROWAVE DATA ALSO INDICATE DRY AIR ENTRAINMENT CONTINUES FROM THE NORTH AND WEST OF THE SYSTEM. B. TD 06W IS FORECAST TO CONTINUE TO TRACK SLOWLY TO THE NORTHEAST IN THE EARLY PERIOD UNDER THE INFLUENCE OF THE STEERING RIDGE TO THE EAST OF THE SYSTEM. AFTERWARDS, TRACK SPEED IS FORECAST TO INCREASE AS THE SYSTEM FALLS UNDER THE INFLUENCE OF THE MID- LATITUDE WESTERLIES, BEGINNING EXTRATROPICAL TRANSITION BY THE END OF THE FORECAST PERIOD. THE AVAILABLE DYNAMIC AIDS CONSISTING OF NOGAPS, UKMET (EGRR), GFDN, THE JAPANESE GLOBAL (JGSM) AND TYPHOON MODELS (JTYM), NCEP GFS AND COAMPS FALL INTO TWO CLUSTERS WITH REGARD TO THIS FORECAST. COAMPS, NOGAPS AND AVN (IN THE EARLY PERIOD) KEEP THE SYSTEM UNDER A WEAKER STEERING INFLUENCE, REMAINING ALMOST QUASI-STATIONARY IN THE SOUTH CHINA SEA AND THEREFORE, REMAINING OUTSIDE THE INFLUENCE OF THE MID-LATITUDE WESTERLIES. THIS IS A POSSIBLE ALTERNATE SCENARIO FOR THIS SYSTEM AND WILL BE CLOSELY MONITORED FOR SUCH. THIS FORECAST IS BASED ON PERSISTENCE AND A CONSENSUS OF ALL THE DYNAMIC AIDS WITH AN EMPHASIS ON EGRR, JGSM, JTYM, AND GFDN. C. TD 06 REMAINS IN A MODERATE UPPER LEVEL ENVIRONMENT AND WILL DEVELOP AT LESS THAN A CLIMATOLOGICAL RATE. NEAR THE END OF THE PERIOD EXTRATROPICAL TRANSITION AND INCREASING VERTICAL WIND SHEAR WILL HALT TROPICAL DEVELOPMENT. D. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE- SIZED SYSTEM. FORECAST TEAM: BRYANT/DENSON/RONSSE/NUTONGLA// NNNN