WDPN32 PGTW 250300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON (TY) 21W (PARMA)/
WARNING NR 19//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 250000Z7 TO 280000Z0 OCT 2003.
	A. TYPHOON (TY) 21W (PARMA), LOCATED APPROXIMATELY 660 NM
NORTH-NORTHWEST OF WAKE, HAS TRACKED EAST-SOUTHEASTWARD AT 19 KNOTS
OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 242330Z4
MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON
SATELLITE CURRENT INTENSITY ESTIMATES OF 115 AND 127 KNOTS. A
242248Z2 SSM/I PASS DEPICTS EYEWALL EROSION IN THE NORTHWEST QUADRANT.
	B. TY 21W IS EXPECTED TO TRACK EAST-SOUTHEASTWARD ALONG 
THE MID-LEVEL STEERING RIDGE LOCATED TO THE SOUTH. THIS RIDGE IS
EXPECTED TO BUILD THROUGH THE PERIOD, STEERING THE SYSTEM TO THE
SOUTH BY 72 HOURS. THE AVAILABLE DYNAMIC AIDS, CONSISTING OF THE
UKMET (EGRR), JGSM, JTYM, GFDN, NOGAPS, AND NCEP GFS ARE IN FAIR
AGREEMENT. MODEL FIELDS INDICATE THE SYSTEM WEAKENS AND DECOUPLES
BY 24 HOURS, CAUSING THE TRACK TO BE SLOWER AND MORE EQUATORWARD
THAN FORECAST. THIS FORECAST IS BASED ON PERSISTENCE AND A BLEND
OF ALL AVAILABLE DYNAMIC AIDS.
	C. TY 21W IS EXPECTED TO WEAKEN THROUGH THE FORECAST PERIOD
AS IT ENCOUNTERS LESS FAVORABLE ENVIRONMENT AND TRACKS OVER COOLER
SEA SURFACE TEMPERATURES.
	D. CURRENT AND FORECAST WIND RADII ARE BASED ON CLIMATOLOGY
FOR AN AVERAGE SIZED SYSTEM.
3. FORECAST TEAM: WINGEART/WAUGAMAN/ALLEN//

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