WDPN33 PGTW 251500
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W
/WARNING NR 25//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 251200Z0 TO 261200Z1 AUG 2004.
   A. TYPHOON (TY) 20W (AERE), LOCATED ALONG THE COAST OF CHINA
APPROXIMATELY 130 NM WEST-NORTHWEST OF TAIPEI, TAIWAN, HAS
TRACKED WEST-SOUTHWESTWARD AT 11 KNOTS OVER THE PAST 06 HOURS.
THE WARNING POSITION IS BASED ON 251130Z2 ENHANCED INFRARED
SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE
CURRENT INTENSITY ESTIMATES OF 77 AND 90 KNOTS AND A REDUCTION
TO REFLECT RAPID SYSTEM WEAKENING DUE TO LAND INTERACTION.
   B. TY 20W IS FORECAST TO TRACK WESTWARD ALONG THE SOUTHERN
PERIPHERY OF THE MID-LEVEL STEERING RIDGE LOCATED TO THE NORTH
OF THE SYSTEM FOR THE REMAINDER OF THE FORECAST PERIOD. TY 20W
HAS TRACKED OVER THE TAIWAIN STRAIT AND IS MAKING LANDFALL IN THE
VICINITY OF PINGTAN, CHINA. THE AVAILABLE DYNAMIC AIDS CONSISTING
OF NOGAPS, JGSM, JTYM, WBAR, GFDN, NCEP GFS, COAMPS AND AFWA MM5
ARE IN GOOD AGREEMENT WITH THIS SCENARIO. THIS FORECAST IS BASED
ON A CONSENSUS OF ALL AVAILABLE DYNAMIC AIDS.
   C. TY 20W HAS MAINTAINED A POLEWARD OUTFLOW CHANNEL ASSOCIATED
WITH A PASSING SHORTWAVE TROUGH THAT HAS CONTRIBUTED TO STRONG
INTENSITY IN SPITE OF LAND INTERACTION. TY 20W IS FORECAST TO
RAPIDLY WEAKEN AS THE SYSTEM TRACKS OVER LAND FOR THE REMAINDER
OF THE FORECAST PERIOD.
   D. CURRENT WIND WIND RADII ARE BASED ON CLIMATOLOGY FOR AN
AVERAGE TO LARGE SIZED SYSTEM INTERACTING WITH LAND.
3. FORECAST TEAM: DIXON/BOWER/FJELD/VOHS/SPANSKI//

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