WDPN32 PGTW 181500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 13W WARNING NR 01// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 181200Z2 TO 211200Z6 JUL 02. A. TROPICAL DEPRESSION (TD) 13W, LOCATED APPROXIMATELY 50 NM EAST OF TANDAG, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 181130Z4 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 25 KNOTS. ANIMATED ENHANCED INFRARED IMAGERY DEPICTS INCREASING DEEP CONVECTION CENTERED ABOVE A LOW LEVEL CIRCULATION CENTER (LLCC). B. TD 13W IS EXPECTED TO TRACK NORTH-NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF AN EXTENSION OF THE SUBTROPICAL RIDGE LOCATED NORTH-NORTHEAST OF THE SYSTEM. STEERING FOR THIS SYSTEM WILL BE WEAK OVER THE NEXT 48 HOURS AND THERE IS SIGNIFICANT DIVERGENCE IN THE FORECASTED MODEL TRACKS. ONE CLUSTER CONSISTING OF NOGAPS AND GFDN TAKES THE SYSTEM EAST AND INTERACTS WITH STY 12W (FENGSHEN) UNDER THE INFLUENCE OF STEERING FLOW FROM THE SOUTHWEST. THE OTHER CLUSTER CONSISTING OF THE AVIATION MODEL (AVN) TRACKS THE SYSTEM NORTHWESTWARD UNDER THE INFLUENCE OF AN EXTENSION OF THE SUBTROPICAL RIDGE TO THE NORTHEAST. OUR FORECAST IS A BLEND OF ALL AVAILABLE DYNAMIC AIDS WITH AN EMPHASIS ON PERSISTENCE AND AVN IN THE EARLY PERIOD. C. TD 13W IS EXPECTED TO SLOWLY INTENSIFY THROUGH 48 HOURS WHILE EMBEDDED IN THE MONSOON TROUGH, AND THEN INTENSIFY AT A NEAR CLIMATOLOGICAL RATE UNDER MORE FAVORABLE UPPER LEVEL CONDITIONS. D. WIND RADII ANALYSIS IS BASED ON MICROWAVE IMAGERY AND QUIKSCAT. FORECAST WIND RADII IS BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE SYSTEM. 3. FORECAST TEAM: BRYANT/JACOBS/SHERRY/NUTONGLA// NNNN