WDPN31 PGTW 250300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON (TY) 20W (KETSANA)/
WARNING NR 26//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 250000Z7 TO 270000Z9 OCT 2003.
       A. TYPHOON (TY) 20W (KETSANA), LOCATED APPROXIMATELY 310 NM
WEST OF IWO JIMA, HAS TRACKED NORTH-NORTHEASTWARD AT 16 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 90 KNOTS. A 242144Z7 SSM/I
PASS DEPICTS EROSION OF THE EYEWALL AND DRY AIR ENTRAINMENT.
       B. TY 20W CONTINUES TO TRACK NORTHEASTWARD ALONG THE WESTERN
PERIPHERY OF THE MID-LEVEL STEERING RIDGE LOCATED TO THE EAST OF
THE SYSTEM. A SHORTWAVE TROUGH OVER THE KOREAN PENINSULA IS
EXPECTED TO DEEPEN AND PROPAGATE EASTWARD THROUGH THE FORECAST
PERIOD, AND INTERACT WITH TY 20W. THE SYSTEM HAS BEGUN TO
TRANSITION INTO AN EXTRATROPICAL SYSTEM. THE AVAILABLE DYNAMIC AIDS,
CONSISTING OF NOGAPS, UKMET (EGRR), JGSM, JTYM, GFDN, AND NCEP GFS
ARE IN GOOD AGREEMENT WITH THIS SCENARIO. THIS FORECAST IS BASED ON
A CONSENSUS OF THE AVAILABLE AIDS.
       C. TY 20W IS FORECAST TO WEAKEN AS IT ENCOUNTERS INCREASING
VERTICAL WIND SHEAR 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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