WDPN31 PGTW 250300 
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 31W (FAXAI) WARNING NR 54//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 250000Z7 TO 271200Z2 DEC 01.
   A. TYPHOON (TY) 31W (FAXAI), LOCATED APPROXIMATELY 1000 NM WEST-
NORTHWEST OF WAKE ISLAND, HAS TRACKED NORTHEASTWARD AT 24 KNOTS 
DURING THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 242330Z4 
INFRARED AND VISIBLE SATELLITE IMAGERY. THE WARNING INTENSITY IS 
BASED ON CURRENT INTENSITY ESTIMATES OF 77 AND 90 KNOTS. ANIMATED 
VISIBLE SATELLITE IMAGERY DEPICTS SIGNIFICANT DECREASE OF DEEP 
CLOUDINESS AND BANDS OVER THE WESTERN QUADRANT INDICATIVE OF EXTRA-
TROPICAL TRANSITION. CONFLUENT FLOW BETWEEN THE POLEWARD OUTFLOW 
CHANNEL FROM THE SYSTEM AND THE PFJ IS GENERATING A LARGE CIRRUS 
SHIELD TOWARD THE NORTHEAST. A RECENT SSM/I PASS REVEALS THAT THE 
DEEP CONVECTION IS LIMITED TO THE NORTHEASTERN QUADRANT. 
   B. TY 31W CONTINUES TO TRACK QUICKLY TOWARDS THE NORTHEAST UNDER 
THE STEERING INFLUENCE OF MID-LEVEL SOUTHWESTERLIES ASSOCIATED WITH 
A MID-LATITDUE TROUGH. THE DYNAMIC AIDS STILL SHOW DISPARITY IN HOW 
THEY HANDLE THE EXTRA-TROPICAL TRANSITION. JMA TYPHOON MODEL AND 
GFDN INDICATE A COMPLEX TRANSITION (NEW BAROCLINIC LOW DEVELOPMENT 
ALONG A FRONTAL BOUNDARY) BETWEEN THE 18 AND 30 HOUR TIMEFRAME. THE 
UKMET SPECTRAL, AVN, NOGAPS, COAMPS,  AFWA MESOSCALE (MM5), AND THE 
JMA GLOBAL SHOW A COMPOUND TRANSITION (MERGE WITH A BAROCLINIC LOW) 
BY 30 HOURS. OUR FORECAST IS BASED ON THE LARGER GROUP SIGNIFYING A 
COMPOUND TRANSITION.
   C. A WEAKENING TREND SHOULD CONTINUE THROUGH THE EARLY STAGES OF 
THE TRANSITION AS THE UPPER LEVEL SOUTHWESTERLIES CONTINUE TO SHEAR 
THE DEEP CONVECTION. LATE IN THE PERIOD, A SLIGHT INTENSIFICATION 
MAY RESULT AFTER EXTRA-TROPICAL TRANSITION.
   D. WIND RADII ANALYSIS IS BASED ON MICROWAVE IMAGERY. WIND RADII 
FORECAST THROUGH 12 HOURS IS BASED ON CLIMATOLOGY. FOR GALE AND SEA 
HEIGHT INFORMATION ON XT POSITIONS, REFER TO WWPW30 RJTX BULLETIN.
FORECAST TEAM: VILPORS/KENDALL/CUTMAN/NUTONGLA//



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