WDPN33 PGTW 090300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 19W (PARMA)// WARNING NR 46// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 19W (PARMA) CONTINUES TO TRACK TO THE WEST AND HAS MOVED BACK INTO THE SOUTH CHINA SEA; THE SYSTEM IS STEERING UNDER THE INFLUENCE OF THE SUBTROPICAL RIDGE (STR) LOCATED TO THE NORTHWEST. CONTINUAL LAND INTERACTION WITH NORTHERN LUZON HAS WEAKENED THE SYSTEM. RECENT ANIMATED MULTISPECTRAL IMAGERY SHOWS DEEP CONVECTION CONCENTRATED TO THE SOUTH AND WEST OF THE LOW LEVEL CIRCULATION CENTER (LLCC), INDICATING THAT THE SYSTEM MAY BE UNDERGOING UNFAVORABLE VERTICAL WIND SHEAR. THE INITIAL INTENSITY OF 30 KNOTS IS BASED ON A 082156Z QUIKSCAT PASS SHOWING UNFLAGGED 30KT WINDS IN THE FLOW AWAY FROM LAND INTERACTIONS. 3. FORECAST REASONING A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS FORECAST REASONING BULLETIN. B. LOW TO MID-LEVEL RIDGING IS EXPECTED TO SLOWLY REBUILD OVER SOUTHERN CHINA AND WILL GUIDE THE SYSTEM TO THE WEST OVER THE NEXT 5 DAYS. A MAXIMUM INTENSITY OF 40 KNOTS IS POSSIBLE AS THE LOW LEVEL RECONSOLIDATES IN THE SOUTH CHINA SEA UNDER GENERALLY FAVORABLE UPPER LEVEL CONDITIONS. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH ALL AIDS SHOWING A TRACK SLIGHTLY NORTH OF WEST TOWARDS SOUTHERN HAINAN ISLAND. C. BEYOND TAU 72 THE RIDGE TO THE NORTH WILL CONTINUE TO BUILD AND THE SYSTEM SHOULD CONTINUE TO ACCELERATE, AND MAY EVEN START TO TRACK SLIGHTLY SOUTH OF WEST AS THE RIDGE PUSHES TO THE SOUTH, BEFORE MAKING LANDFALL NORTH OF HUE, VIETNAM.// NNNN