WDPN31 PGTW 061500
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 08W (CHATAAN) WARNING 
NR 35//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 061200Z9 TO 091200Z2 JUL 02.
   A. TYPHOON (TY) 08W (CHATAAN), LOCATED APPROXIMATELY 475 NM 
SOUTH-SOUTHWEST OF IWO JIMA, HAS TRACKED NORTHWESTWARD AT 09 KNOTS 
OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 061130Z1 
ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED 
ON SATELLITE CURRENT INTENSITY ESTIMATES OF 115 KNOTS. ANIMATED 
ENHANCED INFRARED IMAGERY INDICATES THE SYSTEM IS UNDER EASTERLY 
WIND SHEAR ASSOCIATED WITH THE MID-LEVEL RIDGE NORTH OF THE SYSTEM.  
   B. TY 08W IS EXPECTED TO CONTINUE TRACKING NORTHWESTWARD, GUIDED 
BY THE MID-LEVEL RIDGE TO THE NORTH, THROUGH 48 HOURS AND THEN BEGIN 
TO TURN NORTH-NORTHWEST TOWARDS A WEAKNESS IN THE SUBTROPICAL RIDGE. 
THE AVAILABLE DYNAMIC AIDS CONSISTING OF AVN, NOGAPS, GFDN, COAMPS, 
THE UK-MET GLOBAL, AFWA MESOSCALE (MM5), AND THE JAPANESE GLOBAL 
(JGSM) AND TYPHOON (JTYM) MODELS ARE IN EXCELLENT AGREEMENT. OUR 
FORECAST IS A BLEND OF ALL AVAIABLE AIDS.  
   C. TY 08W IS EXPECTED TO SLOWLY WEAKEN AS IT ENCOUNTERS COOLER 
SEA SURFACE TEMPERATURES. HOWEVER, THIS WEAKENING EFFECT WILL BE 
COUNTERED BY A DECREASE IN VERTICAL SHEAR AS THE SYSTEM PROPAGATES 
TOWARDS THE SOUTHWEST QUADRANT OF THE MID-LEVEL RIDGE.  
   D. WIND RADII ANALYSIS BASED ON A 060816Z1 QUIKSCAT PASS. 
FORECAST WIND RADII BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE SYSTEM. 
3. FORECAST TEAM: LEEJOICE/AYALA/HARRISON/BOSTIC//

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