WDPN31 PGTW 141500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 04W (NIDA) WARNING /NR 05// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 141200Z8 TO 191200Z3 MAY 2004. A. TYPHOON (TY) 04W (NIDA), LOCATED APPROXIMATELY 230 NM WEST-NORTHWEST OF PALAU, HAS TRACKED NORTHWESTWARD AT 04 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 141130Z0 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 55 AND 65 KNOTS. ANIMATED WATER VAPOR SATELLITE IMAGERY INDICATES THAT ENHANCED EQUATORWARD OUTFLOW CONTINUES. RECENT MICROWAVE SATELLITE IMAGERY INDICATES AN EYE DEVELOPING AT 37 GHZ, HOWEVER THIS FEATURE IS NOT FULLY REFLECTED IN ENHANCED INFRARED IMAGERY. B. TY 04W IS FORECAST TO TRACK NORTHWESTWARD THROUGH 72 HOURS UNDER THE INFLUENCE OF A MID-LEVEL SUBTROPICAL RIDGE NORTH OF THE SYSTEM. AN APPROACHING SHORTWAVE TROUGH TO THE NORTH IS EXPECTED TO BEGIN WEAKENING THE RIDGE IN THE MID-PERIOD, CAUSING A MORE POLEWARD TRACK CHANGE. THE AVAILABLE DYNAMIC AIDS, CONSISTING OF NOGAPS, GFDN, EGRR, NCEP GFS, JTYM, AFWA MM5, COAMPS AND JGSM ARE IN GOOD AGREEMENT WITH THIS SCENARIO. THIS FORECAST IS BASED ON A CONSENSUS OF ALL AVAILABLE DYNAMIC AIDS AND PERSISTENCE. C. AN UPPER LEVEL TROUGH NORTH OF THE SYSTEM IS SLIGHTLY ENHANCING OUTFLOW AND EQUATORWARD OUTFLOW CONTINUES TO BE EXCELLENT. TY 04W IS FORECAST TO CONTINUE TO INTENSIFY AT A CLIMATOLOGICAL RATE THROUGH 48 HOURS WHILE IN A FAVORABLE ENVIRONMENT. AS TY 04W APPROACHES LUZON, OUTFLOW IS EXPECTED TO WEAKEN AND INTERACTION WITH LAND WILL CAUSE INTENSIFICATION TO CEASE. D. INITIAL AND FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE-SIZED SYSTEM. E. THE EXTENDED FORECAST CALLS FOR AN APPROACHING TROUGH TO WEAKEN THE STEERING RIDGE. TY 04W IS EXPECTED TO TRACK POLEWARD INTO THE WEAKNESS IN THE RIDGE AND SLOWLY WEAKEN AS IT RECURVES TOWARDS THE NORTHEAST IN A LESS FAVORABLE UPPER LEVEL ENVIRONMENT. 3. FORECAST TEAM: BRYANT/HEATH/VOHS// NNNN