WDPN31 PGTW 110300 
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 27W (LINGLING) WARNING 
NR 21//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 110000Z2 TO 140000Z5 NOV 01.
   A. TYPHOON (TY) 27W (LINGLING), LOCATED APPROXIMATELY 180 NM EAST 
OF VIETNAM, HAS TRACKED WESTWARD AT 09 KNOTS DURING THE PAST SIX 
HOURS. THE WARNING POSITION IS BASED ON 102330Z9 INFRARED AND 
VISIBLE SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON 
SATELLITE CURRENT INTENSITY ESTIMATES OF 115 KNOTS. MAXIMUM 
SIGNIFICANT WAVE HEIGHT AT 110000Z2 IS 31 FEET. ANIMATED INFRARED 
IMAGERY AND MICROWAVE PASS SERIES DEPICT THAT THE NORTHEAST 
PORTION OF THE EYEWALL HAS ERODED OVER THE PAST 12 HOURS. 
   B. A MID-LEVEL HIGH SITUATED OVER LAOS IS FORECAST TO WEAKEN AND 
RETROGRADE THROUGH THE PERIOD. THE AVAILABLE DYNAMIC AIDS INCLUDE 
NOGAPS, UK-MET OFFICE GLOBAL, NCEP AVIATION, THE JMA GLOBAL SPECTRAL 
AND TYPHOON MODELS. ALL THE MODELS ARE IN AGREEMENT, HOWEVER, THE 
JMA GLOBAL INDICATES A MORE NORTHWESTWARD BIAS. OUR FORECAST IS 
BASED ON PERSISTENCE AND A BLEND OF THE AFOREMENTIONED MODELS.
   C. A 24 HOUR TREND OF THE 300 AND 200 MB LEVELS REVEAL THAT 
CYCLONIC OUTFLOW HAS BEEN REPLACED BY EASTERLY DIFFLUENT FLOW. ALSO, 
THE UPPER WIND STRENGTH HAS INCREASED TO 45 KNOTS OVER THE 
NORTHEASTERN QUADRANT, HENCE, THE EROSION TREND. IT ALSO APPEARS 
THAT THE SUBTROPICAL RIDGE IS BEGINNING TO BUILD BACK OVER THE 
TAIWAN STRAIT WHICH WOULD FURTHER SUPPORT THE EASTERLY COMPONENT 
OVER THE SYSTEM. SST ANAL DEPICTS A TONGUE OF COOLER WATER (22 TO 24 
CELSIUS) EXTENDING SOUTH FROM THE TAIWAN STRAIT. THEREFORE, OUR 
FORECAST WILL REFLECT A SLOW WEAKENING TREND BEFORE LANDFALL.
   D. WIND RADII FOR INITIAL POSITION IS BASED ON A RECENT QUIKSCAT 
PASS. FORECAST RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE 
SYSTEM.
FORECAST TEAM: LEEJOICE/ROBERTS/WHITCOMB/HARRISON/EDBERG/BOSTIC//