WDPN32 PGTW 121500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (PHANFONE) WARNING NR 07// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 121200Z6 AUG TO 151200Z9 AUG 02. A. TROPICAL STORM (TS) 19W (PHANFONE), LOCATED APPROXIMATELY 300 NM NORTH-NORTHWEST OF POHNPEI, HAS TRACKED NORTH-NORTHWESTWARD AT 06 KNOTS OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 121130Z8 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 45 AND 55 KNOTS. A RECENT QUIKSCAT PASS SHOWS THAT TS 19W REMAINS EMBEDDED IN THE MONSOON TROUGH WITH STRONG EQUATORIAL WESTERLIES SOUTH OF THE SYSTEM. B. TS 19W IS EXPECTED TO CONTINUE TRACKING NORTH-NORTHWESTWARD OUT OF THE MONSOON TROUGH DURING THE EARLY PERIOD. AFTERWARDS TS 19W IS FORECAST TO TRACK NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE LOW TO MID LEVEL RIDGE TO THE NORTH. THE AVAILABLE DYNAMIC AIDS CONSIST OF NCEP AVIATION (AVN), GFDN, NOGAPS, UKMET GLOBAL (EGRR), AFWA, COAMPS, AND THE JAPANESE GLOBAL (JGSM) MODEL. ALL AIDS ARE IN GOOD AGREEMENT WITH THIS SCENARIO WITH THE EXCEPTION OF AVN. AVN TRACKS THE SYSTEM ON A MORE NORTHWARD COURSE FOR MUCH OF THE FORECAST PERIOD AS IT DEVELOPS THE SURFACE LOW TO THE WEST OF TS 19W DRAMATICALLY, WHILE DIMINISHING THE DEVELOPMENT OF TS 19W. THIS SCENARIO SEEMS UNLIKELY CONSIDERING THE CONTINUING DEVELOPMENT OF TS 19W. OUR FORECAST IS BASED ON A BLEND OF PERSISTENCE AND THE AVAILABLE DYNAMIC AIDS WITH LESS EMPHASIS ON AVN. C. THE UPPER LEVEL TROUGH TO THE NORTH-NORTHWEST SHOULD CONTINUE TO MOVE WESTWARD AND PROVIDE FAVORABLE POLEWARD OUTFLOW. DUE TO THIS AND FAVORABLE CROSS-EQUATORIAL OUTFLOW PROVIDED BY THE NEAR EQUATORIAL RIDGE, TS 19W IS EXPECTED TO INTENSIFY AT A CLIMATOLOGICAL OR GREATER RATE THROUGHOUT THE FORECAST PERIOD. D. CURRENT WIND RADII ARE BASED ON A RECENT QUIKSCAT PASS. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE SYSTEM. FORECAST TEAM: BRYANT/JACOBS/HEATH/SHERRY/NUTONGLA// NNNN