WDPN31 PGTW 171500 
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON (TY) 14W (PABUK) WARNING 
NR 15//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 171200Z1 TO 201200Z5 AUG 01.
   A. TYPHOON (TY) 14W (PABUK), LOCATED APPROXIMATELY 265 NM 
SOUTHWEST OF THE ISLAND OF IWO JIMA, HAS TRACKED WEST-NORTHWESTWARD 
AT 02 KNOTS DURING THE PAST SIX HOURS. THE WARNING POSITION IS BASED 
ON 171130Z3 INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS 
BASED ON CURRENT SATELLITE INTENSITY ESTIMATES OF 77 AND 89 KNOTS.  
ANIMATED SATELLITE IMAGERY DEPICTS THE NORTHERN PORTION OF THE EYE-
WALL HAS DETERIORATED OVER THE PAST 12 HOURS.   
   B. TY 14W IS CURRENTLY TRACKING WITHIN EASTERLY FLOW ASSOCIATED 
WITH THE LOW TO MID-LEVEL RIDGE NORTH OF THE SYSTEM AND SOME WEAK 
SOUTHERLY FLOW FROM A RIDGE POSITIONED TO THE EAST-SOUTHEAST. THE 
AVAILABLE DYNAMIC AIDS ARE IN FAIR AGREEMENT. THE JMA TYPHOON (JTYM) 
MODEL TRACKS THE SYSTEM NORTHWARD THROUGH THE FORECAST. THE JMA 
GLOBAL SPECTRAL (JGSM) MODEL AND NOGAPS (NGPS) TRACK THE SYSTEM 
GENERALLY NORTHWESTWARD. THE UK MET OFFICE GLOBAL (EGRR) MODEL 
TRACKS THE SYSTEM WESTWARD THROUGH THE 48 HOUR PERIOD AND THEN MORE 
NORTHWESTWARD. THE GEOPHYSICAL FLUID DYNAMICS NAVY (GFDN) MODEL 
HAS TROUBLE INITIALIZING ON THE SYSTEM, THUS DOES NOT PROVIDE A 
FORECASTED TRACK. THE MODELS CONTINUE TO HAVE DIFFICULTY HANDLING 
THE COMPLEX SITUATION OF A MID LEVEL STEERING RIDGE POSITIONED
BOTH TO THE NORTH AND TO THE EAST-SOUTHEAST OF THE SYSTEM. 
ADDITIONALLY, EGRR, NGPS, AND JGSM ALL SHOW SIGNS OF EXCESSIVE 
INTERACTION WITH A DEVELOPING LOW AND MONSOON TROUGH EXTENDING INTO 
THE SOUTH CHINA SEA. THE OFFICIAL FORECAST TRACKS THE SYSTEM 
NORTHWESTWARD TO NORTH-NORTHWESTWARD, BASED ON THE MID LEVEL RIDGE 
TO THE EAST STRENGTHENING AND BECOMING THE DOMINANT STEERING 
MECHANISM. ALSO, A MID-LATITUDE TROUGH SHOULD PUSH SOUTH INTO THE 
YELLOW SEA LATE IN THE FORECAST PERIOD, WEAKENING THE RIDGE NORTH OF 
THE SYSTEM AND ALLOWING THE SYSTEM TO TRACK MORE NORTHWARD. THE 
OFFICIAL FORECAST IS BASED ON THE NUMERICAL CONSENSUS OF THE 4 
MODELS (JTYM, JGSM, NGPS, AND EGRR) BLENDED WITH PERSISTENCE.  
   C. TY 14W IS EXPECTED TO SLOWLY INTENSIFY THROUGH THE FORECAST 
PERIOD AS IT TRACKS THROUGH A FAVORABLE UPPER LEVEL ENVIRONMENT.
   D. FORECAST WIND RADII ARE BASED ON SYNOPTIC REPORTS, A RECENT 
QUIKSCAT GALE WIND ANALYSIS AND CLIMATOLOGY FOR A LARGE SYSTEM.
FORECAST TEAM: MAZANY/MORRIS/EDBERG//