WDPN31 PGTW 150300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON (TY) 03W (SUDAL) WARNING /NR 45// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 150000Z6 TO 180000Z9 APR 2004. A. TYPHOON (TY) 03W (SUDAL), LOCATED APPROXIMATELY 140 NM WEST-SOUTHWEST OF IWO JIMA, HAS TRACKED NORTHEASTWARD AT 14 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 142330Z3 MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 90 KNOTS. EXTRATROPICAL TRANSITION HAS COMMENCED AND IS EXPECTED TO BE COMPLETE BY APPROXIMATELY TAU 36. B. TRACK SPEED FOR THE SYSTEM CONTINUES TO INCREASE AS THE SYSTEM INTERACTS WITH THE WESTERLIES. TRACK SPEED HAS SLOWED OVER THE PAST SIX HOURS, HOWEVER, IT IS CONSIDERED THAT THIS VELOCITY DECREASE IS TEMPORARY AND THE RESULT OF THE LOW-LEVEL CIRCULATION CENTER BECOMING EXPOSED TO THE SOUTHWEST OF THE DEEP CONVECTION. VERTICAL WIND SHEAR HAS BEEN INCREASING AS THE SYSTEM CONTINUES TO TRACK POLEWARD ALONG THE NORTHWESTERN PERIPHERY OF THE STEERING RIDGE TO THE SOUTHEAST OF THESYSTEM. ALL OF THE AVAILABLE DYNAMIC AIDS CONSISTING OF NOGAPS, EGRR, GFDN, NCEP GFS, COAMPS, AFWA, TLAPS, TCLAPS, JGSM, JTYM, AND WBAR ARE IN EXCELLENT AGREEMENT. THE FORECAST IS BASED ON A BLEND OF ALL THE AVAILABLE DYNAMIC AIDS. C. TY 03W CONTINUES TO WEAKEN AS IT TRANSITIONS INTO AN EXTRATROPICAL SYSTEM. RECENT MULTISPECTRAL SATELLITE IMAGERY INDICATES A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION (LLCC) TO THE SOUTHWEST. TY 03W IS FORECAST TO CONTINUE WEAKENING THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD AS IT CONTINUES TO ENCOUNTER INCREASING VERTICAL WIND SHEAR AND DECREASING SEA SURFACE TEMPERATURES WHILE UNDERGOING EXTRATROPICAL TRANSITION. D. CURRENT AND FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZED SYSTEM AND FOR A SYSTEM UNDERGOING EXTRATROPICAL TRANSITION. RELEASED BY: LT DIXON, USN. FORECAST TEAM: DIXON/MENEBROKER/FUNK// NNNN