WDPN32 PGTW 151500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W (PHANFONE) WARNING NR 19// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 151200Z9 AUG TO 181200Z2 AUG 02. A. TYPHOON (TY) 19W (PHANFONE), LOCATED APPROXIMATELY 220 NM EAST-SOUTHEAST OF IWO JIMA, HAS TRACKED NORTHWESTWARD AT 14 KNOTS OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 151130Z1 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 102 TO 127 KNOTS. ENHANCED INFRARED SATELLITE IMAGERY REVEALS A 10 NM SYMMETRICAL EYE. B. THE MID TO HIGH-LEVEL SUBTROPICAL RIDGE NORTH OF TY 19W IS EXPECTED TO REMAIN IN PLACE THROUGHOUT THE EARLY PERIOD. TY 19W IS EXPECTED TO TRACK NORTHWESTWARD ALONG THE SOUTHWESTERN EDGE OF THAT SUBTROPICAL RIDGE THROUGHOUT THE EARLY PERIOD. AFTER THE 36- HOUR FORECAST PERIOD, THE RIDGE IS EXPECTED TO WEAKEN AND REORIENT TO THE EAST, CREATING A MORE POLEWARD TRACK. THE AVAILABLE DYNAMIC AIDS, CONSISTING OF NCEP AVIATION (AVN), GFDN, NOGAPS (NGPS), UKMET GLOBAL (EGRR), AFWA, COAMPS, AND THE JAPANESE GLOBAL (JGSM) AND TYPHOON (JTYM) MODELS ARE IN GOOD AGREEMENT WITH THIS SCENARIO, WITH THE EXCEPTION OF EGRR. AFTER 36 HOURS, EGRR TAKES A SLIGHTLY MORE WESTWARD TRACK THAN THE OTHER MODELS. OUR FORECAST IS BASED ON A BLEND OF PERSISTENCE AND ALL AVAILABLE DYNAMIC AIDS WITH LESS EMPHASIS ON EGRR. C. A TROUGH EAST OF THE SYSTEM WILL CONTINUE TO ENHANCE OUTFLOW CONDITIONS AND THE NEAR EQUATORIAL RIDGE SOUTHEAST OF THE SYSTEM IS EXPECTED TO CONTINUE TO PROVIDE CROSS-EQUATORIAL OUTFLOW THROUGH THE NEXT 12 TO 24 HOURS. TY 19W WILL REACH THE MAXIMUM INTENSITY IN THE NEXT 12 TO 18 HOURS, AT SUPERTYPHOON STRENGTH, FOR THE CURRENT ENVIRONMENT AND WILL THEN MAINTAIN INTENSITY THROUGHOUT THE REMAINDER OF THE EARLY PERIOD. AS THE SYSTEM BEGINS A MORE POLEWARD TRACK COLDER SEA SURFACE TEMPERATURES AND INCREASING VERTICAL WIND SHEAR WILL BEGIN TO DECREASE THE STORM INTENSITY. D. CURRENT WIND RADII ARE BASED ON A RECENT PARTIAL QUIKSCAT PASS. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR A LARGE-SIZED SYSTEM. FORECAST TEAM: BRYANT/JACOBS/HEATH/SHERRY/NUTONGLA// NNNN