WDPN31 PGTW 131500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (NAKRI) WARNING NR 022//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 34.3N 145.3E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 255 NM EAST-SOUTHEAST OF NARITA AIRPORT
   MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 21 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS LITTLE
CHANGE IN THE INTENSITY OF TYPHOON (TY) 29W (NAKRI) AS EVIDENCED BY
FAIRLY STEADY CLOUD TOPS TEMPERATURES IN EIR IMAGERY. AS THE SYSTEM 
HAS TRACKED NORTHEASTWARD, STEERED BY AN ELONGATED SUBTROPICAL RIDGE 
(STR) TO THE SOUTH, EQUATORWARD OUTFLOW HAS DECREASED. STRONG 
POLEWARD OUTFLOW NOW STANDS OUT AS THE PRIMARY EXHAUST MECHANISM. 
CURRENT ENVIRONMENTAL CONDITIONS CONTINUE TO BECOME MORE UNFAVORABLE 
FOR TY NAKRI WITH COOLING SEA SURFACE TEMPERATURES (25 C TO 26 C), 
HIGH VERTICAL WIND SHEAR (25-30 KTS), AND A SIGNIFICANT AMOUNT OF DRY
AIR WRAPPING INTO THE CORE OF THE VORTEX. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON 131121Z METOP-B SCATTEROMETER
DATA. THE INITIAL INTENSITY IS ALSO PLACED WITH HIGH CONFIDENCE
BASED ON THE AFOREMENTIONED ASCAT AND OBJECTIVE ESTIMATES LISTED
BELOW.

INITIAL WIND RADII BASIS: A 131121Z METOP-B SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   RJTD: T4.5 - 77 KTS
   RCTP: T4.5 - 77 KTS
   CIMSS ADT: 49 KTS AT 131130Z
   CIMSS AIDT: 63 KTS AT 131130Z
   CIMSS D-PRINT: 66 KTS AT 131330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 25-30 KTS
   SST: 25-26 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: HIGH

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TYPHOON (TY) 29W (NAKRI) WILL CONTINUE
EAST-NORTHEASTWARD FOR THE REMAINDER OF THE FORECAST PERIOD.
ENVIRONMENTAL CONDITIONS ARE FORECAST TO INCREASINGLY DETERIORATE
WITH THE CIRCULATION ENCOUNTERING EVEN HIGHER WIND SHEAR (35-45
KTS) AND COOLING SEA SURFACE TEMPERATURES (24 C TO 25 C), WHILE
CONTINUING TO ENTRAIN DRY AIR INTO THE CORE OF THE SYSTEM.
EXTRATROPICAL TRANSITION (ETT) WILL COMMENCE AROUND TAU 24. THOUGH
THE FORECASTED ENVIRONMENTAL SETUP SUGGESTS THAT THE SYSTEM COULD 
COMPLETE THE ETT CYCLE SOON AFTER TAU 36, THE JTWC FORECAST
MAINTAINS THAT TY NAKRI WILL BECOME FULLY EXTRATROPICAL AT OR PRIOR 
TO TAU 48, AT AN INTENSITY OF AROUND 35 KTS.

MODEL DISCUSSION: MODELS ARE IN GOOD AGREEMENT WITH A CROSS-TRACK
SPREAD UNDER 60 NM THROUGHOUT THE FORECAST. THE HIGH CONFIDENCE
JTWC TRACK IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS. INTENSITY
GUIDANCE HAS A 10 KNOT SPREAD WITH HAFS-A BEING A BIT RELUCTANT TO
BRING THE STRENGTH OF THE SYSTEM DOWN. THE REMAINING MODELS AGREE
ON A STEEP WEAKENING TREND EXPECTED AFTER TAU 24, AS THE SYSTEM
UNDERGOES EXTRATROPICAL TRANSITION (ETT). THE FORECAST INTENSITY IS
PLACED WITH HIGH CONFIDENCE AND THE JTWC OFFICIAL FORECAST IS WITHIN 
5 KTS OF THE MULTI-MODEL CONSENSUS.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: HIGH//
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