WDPN31 PGTW 260300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION (TD) 17W/ WARNING NR 07// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 260000Z8 TO 290000Z1 SEP 2003. A. TROPICAL DEPRESSION (TD) 17W, LOCATED APPROXIMATELY 610 NM SOUTH-SOUTHWEST OF IWO JIMA, HAS REMAINED QUASISTATIONARY OVER THE PAST 12 TO 18 HOURS. THE WARNING POSITION IS BASED ON 252330Z5 MULTISPECTRAL SATELLITE IMAGERY. THE WARNING POSITION IS RELOCATED BASED ON MULTISPECTRAL SATELLITE IMAGERY THAT INDICATES THE PREDOMINATE LOW LEVEL CIRCULATION CENTER (LLCC) IS APPROXIMATELY 60 NM EQUATORWARD OF THE PREVIOUS WARNING POSITION. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 25 AND 30 KNOTS. A WESTWARD WIND BURST HAS ELONGATED AND HAS REORIENTED THE MONSOON TROUGH TO THE NORTH- EAST. RECENT ANIMATED VISIBLE SATELLITE IMAGERY INDICATES WEAKENING DEEP CONVECTION AND MULTIPLE LLCC'S. THE TUTT CELL TO THE NORTHEAST CONTINUES TO SUPPRESS DEVELOPMENT AND CURB DEEP CONVECTIVE ACTIVITY ON THE POLEWARD SIDE. B. TD 17W IS EXPECTED TO REMAIN NEARLY QUASISTATIONARY FOR THE THE NEXT 12 TO 18 HRS AS IT CONSOLIDATES AFTER THE PASSING OF THE WESTERLY WIND BURST. AFTERWARDS, TD 17W IS FORECAST TO TURN TO THE NORTH EAST WITH THE DEVELOPMENT NEAR THE EQUATORIAL RIDGE AND A SHIFT IN THE MID-LEVEL SUBTROPICAL RIDGE. THIS TRANSITION WILL BE AIDED BY THE PASSAGE OF A SHORTWAVE TROUGH DURING THE NEXT 12 HOURS PASSING OVER JAPAN. TD 17W IS EXPECTED TO SLOWLY TRACK NORTH- NORTHEAST THROUGH THE REMAINDER OF THE FORECAST PERIOD ALONG THE WESTERN EXTENT OF THE RE-ORIENTED SUBTROPICAL RIDGE. THE AVAILABLE DYNAMIC AIDS, NOGAPS, COAMPS, UKMET EGRR, GFS, GFDN, AND JAPAN GLOBAL (JGSM) AND TYPHOON (JTYM) ARE IN FAIR AGREEMENT WITH THIS FORECAST SCENARIO. HOWEVER, THIS SCENARIO HAS BEEN OVER-FORECASTED IN THE DYNAMIC MODELS OVER THE LAST 36 HOURS AS EVIDENCED BY THE WESTWARD PROPAGATION AND THE SLOW TRANSITION TO A POLEWARD TRACK. THE UKMET GLOBAL HAS THE BEST CONTINUITY WITH RESPECT TO INITIALIZATION AND SLOW SPEED OF ADVANCE OVER THE PAST 24 HOURS. THIS FORECAST IS BASED ON A CONSENSUS OF THE AVAILABLE DYNAMIC AIDS WITH AN EMPHASIS ON EGRR. C. TD 17W HAS BEEN SLOW TO DEVELOP WITH THE PASSING WESTERLY WIND BURST DISRUPTING THE FORMATION OF A LLCC BELOW THE MID-LEVEL CIRCULATION. ALSO, UPPER LEVEL CONVERGENCE WITH THE TUTT CELL SITUATED TO THE NORTHEAST HAS PREVENTED SIGNIFICANT DEVELOPMENT WITHIN 24 HOURS. THE TUTT CELL IS EXPECTED TO BE PICKED UP BY THE PASSING SHORT WAVE TROUGH. TD 17W IS EXPECTED TO INTENSIFY SLOWLY FROM 24 TO 48 HOURS AND THEN INTENSIFY AT A CLIMATOLOGICAL RATE AS POLEWARD OUTFLOW IMPROVES AS THE SYSTEM MOVES NEAR THE UPPER LEVEL RIDGE AXIS. D. FORECAST WIND RADII ARE BASED ON THE HUNTLEY MODEL AND REVIEW OF THE DYNAMIC MODEL WIND FIELDS. 3. FORECAST TEAM: LEEJOICE/JACOBS/NUTONGLA/SCHULTZ// NNNN