WDPN31 PGTW 201500
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON (STY) 12W (FENGSHEN) 
WARNING NR 26//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 201200Z5 TO 231200Z8 JUL 02.
   A. SUPER TYPHOON (STY) 12W (FENGSHEN), LOCATED APPROXIMATELY 700 
NM EAST-NORTHEAST OF SAIPAN, HAS TRACKED NORTHWESTWARD AT 08 KNOTS 
OVER THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 201130Z7 
ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED 
ON SATELLITE CURRENT INTENSITY ESTIMATES OF 127 AND 140 KNOTS. 
ANIMATED WATER VAPOR IMAGERY INDICATES THAT SYSTEM OUTFLOW HAS 
DECREASED OVER THE PAST SIX HOURS AS AN UPPER LEVEL LOW NORTHWEST OF 
THE SYSTEM HAS TRACKED WESTWARD. 
   B. THE MID-LEVEL SUBTROPICAL RIDGE NORTH OF THE SYSTEM IS 
EXPECTED TO CONTINUE TO PROPAGATE EASTWARD THROUGH THE FORECAST 
PERIOD AND LINK UP WITH STY 12W PERIPHERAL RIDGE BY 72 HOURS. STY 
12W IS EXPECTED TO TRACK NORTHWESTWARD THROUGH THE PERIOD ALONG 
THE SUBTROPICAL RIDGE. THE AVAILABLE DYNAMIC AIDS CONSIST OF NCEP 
AVIATION (AVN), GFDN, NOGAPS (NGPS), AFWA MM5, COAMPS, UKMET OFFICE 
GLOBAL (EGRR), AND THE JAPANESE GLOBAL (JGSM) AND TYPHOON (JTYM) 
MODELS. THE DYNAMIC AIDS ARE IN GOOD AGREEMENT WITH THIS SCENARIO, 
BUT VARY IN SPEED. OUR FORECAST IS BASED ON A BLEND OF ALL AVAILABLE 
DYNAMIC AIDS.
   C. STY 12W WEAKENED SLIGHTLY OVER THE PAST SIX HOURS AS AN UPPER 
LEVEL LOW LOCATED NEAR 25.6N3 152.1E9 TRACKED WESTWARD AWAY FROM THE 
SYSTEM, DECREASING THE POLEWARD OUTFLOW. THIS WEAKENING TREND IS 
EXPECTED TO BE SHORT TERM AS A SECOND UPPER LEVEL LOW IS EXPECTED TO 
TRACK WESTWARD AND IMPROVE VENTILATION.     
   D. INITIAL WIND RADII ARE BASED ON RECENT QUIKSCAT PASS. FORECAST 
WIND RADII ARE BASED ON CLIMATOLOGY FOR A SMALL SYSTEM. 
3. FORECAST TEAM: WINGEART/LAM/KUMAGA/STATEN