WDPN32 PGTW 141500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W (PHANFONE) WARNING NR 15// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 141200Z8 AUG TO 171200Z1 AUG 02. A. TYPHOON (TY) 19W (PHANFONE), LOCATED APPROXIMATELY 325 NM NORTHEAST OF SAIPAN, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 141130Z0 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 77 AND 90 KNOTS. ANIMATED INFRARED SATELLITE IMAGERY INDICATES A SIGNIFICANT INCREASE IN DEEP CONVECTION OVER THE PAST 6 HOURS. A 140940Z8 SSM/I PASS DEPICTS A BANDING EYE WITH THE DEEP CONVECTION ON THE NORTHWESTERN SIDE WRAPPING INTO THE LOW LEVEL CIRCULATION CENTER. B. THE MID TO HIGH-LEVEL SUBTROPICAL RIDGE NORTH OF TY 19W IS EXPECTED TO REMAIN STRONG THROUGH THE FORECAST PERIOD. TY 19W IS EXPECTED TO CONTINUE TRACKING NORTHWESTWARD ALONG THE SUBTROPICAL RIDGE. THE AVAILABLE DYNAMIC AIDS CONSIST OF NCEP AVIATION (AVN), GFDN, NOGAPS, UKMET GLOBAL (EGRR), AFWA, COAMPS, AND THE JAPANESE GLOBAL (JGSM) AND TYPHOON (JTYM) MODELS. ALL AIDS GENERALLY AGREE WITH A NORTHWESTWARD TRACK. JTYM MAINTAINS A STRONGER RIDGE THROUGH THE PERIOD, RESULTING IN A MORE WESTWARD AND SLIGHTLY FASTER TRACK. JTYM HAS VERIFIED WELL OVER THE PAST 36 HOURS. THEREFORE, OUR FORECAST IS BASED ON A BLEND OF PERSISTENCE AND ALL AVAILABLE DYNAMIC AIDS, HEDGING TOWARD JTYM EARLY IN THE PERIOD. C. A SHORTWAVE 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 36 TO 48 HOURS. FAVORABLE UPPER LEVEL CONDITIONS WILL CONTINUE AFTER 48 HOURS AS THE SYSTEM APPROACHES THE RIDGE AXIS. TY 19W IS EXPECTED TO INTENSIFY AT A CLIMATOLOGICAL THROUGHOUT THE FORECAST PERIOD. D. CURRENT WIND RADII ARE BASED ON A 140814Z8 QUIKSCAT PASS. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR A LARGE-SIZED SYSTEM. FORECAST TEAM: WINGEART/LAM/KUMAGA/STATEN// NNNN