WDPN32 PGTW 040300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W WARNING NR 12// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 040000Z4 TO 070000Z7 JUL 01. A. TYPHOON (TY) 06W (UTOR), LOCATED APPROXIMATELY 125 NM EAST-NORTHEAST OF PORT SAN VICENTE, LUZON, HAS TRACKED WEST- NORTHWESTWARD AT 21 KNOTS OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 032330Z1 VISIBLE AND INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 77 KNOTS. INFRARED ANIMATION INDICATES DEEP CONVECTION IS STILL MORE ACTIVE IN THE SOUTH SEMI-CIRCLE. B. MID-LEVEL HIGH HEIGHT CENTER SITUATED OVER SOUTHERN JAPAN, WITH ASSOCIATED RIDGE EXTENDING OVER THE COAST OF CHINA, IS FORECAST TO WEAKEN WITH AN APPROACH OF SHORT WAVE TROUGH NEAR THE 24 HOUR PERIOD. THEREFORE, TY 06W MAY SHOW A SLIGHT STAIR STEP WITHIN THE WEAKNESS NEAR TAIWAN BEFORE CONTINUING ON A GENERALLY WEST- NORTHWESTWARD TRACK TOWARD THE CHINA COAST. THE DYNAMIC MODELS ARE IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD, SHOWING MINOR DISAGREEMENT CONCERNING SPEED OF MOVEMENT LATE IN THE FORECAST PERIOD. NOGAPS, GFDN, UKMET, AND THE JMA TYPHOON AND GLOBAL SPECTRAL MODELS WERE TO CREATE THE FORECAST TRACK. THE JAPANESE MODELS CONTINUE TO SHOW THE FASTEST SPEEDS POSSIBLY DUE TO EXCESSIVE DEVELOPMENT OF THE APPROACHING STEERING RIDGE. THE OFFICIAL FORECAST IS BASED ON PERSISTENCE THE NUMERICAL CONSENSUS OF FIVE MODELS. C. TY 06W IS EXPECTED TO INTENSIFY FOR THE NEXT 12 TO 18 HOURS BASED ON WARM SEA SURFACE TEMPS AND THE PRESENCE OF AN EQUATORWARD OUTFLOW CHANNEL. THE INFLUENCE OF STRONGER UPPER EASTERLIES ASSOCIATED WITH AN UPPER HIGH SITUATED EAST OF TAIWAN SHOULD HINDER DEVELOPMENT LATER IN THE FORECAST PERIOD. D. THE WIND RADII ARE BASED ON SYNOPTIC DATA, MICROWAVE IMAGERY AND CLIMATOLOGY FOR A LARGE-SIZED TROPICAL CYCLONE. FORECAST TEAM: SMITH/MAYER/TON// BT #XXXX NNNN