WDPN31 PGTW 220300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON (TY) 20W (KETSANA)/ WARNING NR 14// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 220000Z4 TO 260000Z0 OCT 2003. A. TYPHOON (TY) 20W (KETSANA), LOCATED APPROXIMATELY 720 NM SOUTHWEST OF IWO JIMA, HAS DRIFTED NORTHWARD AT 02 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 212330Z1 MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 127 KNOTS. RECENT MICROWAVE IMAGERY INDICATES THE EYEWALL IS ERODING IN THE NORTHEASTERN QUADRANT. B. TY 20W IS EXPECTED TO CONTINUE TRACKING SLOWLY TO THE NORTH FOR THE NEXT 12 TO 24 HOURS AS A MID-LEVEL PERIPHERAL RIDGE BUILDS TO THE EAST OF THE SYSTEM. TY 20W IS EXPECTED TO INTERACT WITH THE BAROCLINIC ZONE BY MID PERIOD, TRACKING NORTHEASTWARD AND INCREASING SPEED AFTER 24 HOURS. TY 20W IS EXPECTED TO COMPLETE EXTRATROPICAL TRANSITION BY 72 HOURS. THE AVAILABLE DYNAMIC AIDS, CONSISTING OF NOGAPS, UKMET (EGRR), JGSM, JTYM, GFDN, WBAI, COAMPS, AND NCEP GFS ARE IN GOOD AGREEMENT WITH THIS SCENARIO. THIS FORECAST IS BASED ON A CONSENSUS OF AVAILABLE AIDS. C. TY 20W IS EXPECTED TO INTENSIFY SLIGHTLY OVER THE NEXT 12 HOURS, THEN WEAKEN AS IT ENCOUNTERS INCREASING VERTICAL WIND SHEAR FROM WESTERLY FLOW. D. CURRENT AND FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN ABOVE-AVERAGE SIZED SYSTEM. E. THE EXTENDED FORECAST EXPECTS TY 20W TO CONTINUE ON A NORTHEAST TRACK AND TRANSITION COMPLETELY TO AN EXTRATROPICAL SYSTEM BY THE END OF THE FORECAST PERIOD. 3. FORECAST TEAM: WINGEART/ALLEN/MENEBROKER// NNNN