WDPN33 PGTW 210300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (NEOGURI) WARNING NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 27.2N 152.7E
   INITIAL INTENSITY: 125 KTS
   GEOGRAPHIC REFERENCE: 824 NM EAST-SOUTHEAST OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 47 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
THE ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN
AXISYMMETRIC SYSTEM WITH A LARGE, CIRCULAR EYE, WARMING CLOUD TOPS
WHERE THERE WAS ONCE DEEP CONVECTION, AND A SMOOTHED TEXTURE ATOP
THE CDO. ALL OF THESE OBSERVATIONS SUGGEST TYPHOON NEOGURI HAS
BECOME ANNULAR. A 202314Z MHS 89 GHZ IMAGE IS THE LATEST MICROWAVE
IMAGERY TO CAPTURE THE FULL HORIZONTAL EXPANSE OF THE TYPHOON, AND
IT SUPPORTS THE CIRCULAR STRUCTURE NOTED IN THE ANIMATED MSI. THE
OUTFLOW CONTINUES TO BE STRONG RADIAL WITH TRANSVERSE BANDING ON
ALL SIDES. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE POSITION OF THE EYE, WHICH HAS AN EYE TEMPERATURE
RECENTLY MEASURED AT 19C. THE INITIAL INTENSITY OF 125 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON VERY GOOD AGREEMENT OF
OBJECTIVE INTENSITY ESTIMATES AND THE AGENCY SUBJECTIVE DVORAK
FIXES. THE WIND RADII WAS VALIDATED BASED ON A 210007Z METOP-C
ASCAT IMAGE.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE
EAST-NORTHEAST, WITH A COMPETING RIDGE TO THE WEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.5 - 127 KTS
   RJTD: T6.5 - 127 KTS
   RCTP: T6.0 - 115 KTS
   KNES: T6.5 - 127 KTS
   CIMSS SATCON: 132 KTS AT 202106Z
   CIMSS ADT: 124 KTS AT 202030Z
   CIMSS AIDT: 124 KTS AT 202030Z
   CIMSS D-MINT: 123 KTS AT 202106Z
   CIMSS D-PRINT: 130 KTS AT 210110Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 0-5 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG RADIAL

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: WITH TYPHOON 25W TAKING ON AN ANNULAR
APPEARANCE, IT FOLLOWS THAT THE INTENSIFICATION PERIOD WILL LARGELY
STALL, AND THE PEAK OF 130 KTS AT TAU 12 MAY BE THE OVERALL MAXIMUM
THIS SYSTEM IS ABLE TO ACHIEVE. THE ENVIRONMENTAL CONDITIONS ARE
STILL FAVORABLE FOR CONTINUED DEVELOPMENT, BUT SLOWING OF THE
FORWARD MOTION OF NEOGURI WILL BECOME MORE PROBLEMATIC DUE TO AN
ISSUE OF UPWELLING. THE SLOW TRACK IS THANKS TO INFLUENCES BY A
RIDGE TO THE WEST CREATING A COMPETING STEERING MECHANISM, THOUGH
THE RIDGE TO THE EAST IS STILL EXPECTED TO RETAIN DOMINANCE
THROUGHOUT THE DURATION OF THE FORECAST. DUE TO THE NEAR-TERM
DELAYS, AFTER THE SYSTEM RECURVES AROUND THE SUBTROPICAL RIDGE
AXIS, IT IS MORE LIKELY TO DIRECTLY ENCOUNTER AN INCOMING
MID-LATITUDE TROUGH. THE TYPHOON WILL ACCELERATE AFTER TAU 72 DUE
TO INTERACTION WITH THE TROUGH, AND THE INCREASE IN TRACK SPEEDS
WILL HELP TO ARTIFICIALLY KEEP THE SYSTEM INTENSITY HIGH.
ADDITIONALLY, INTERACTION WITH THE TROUGH WILL RESULT IN WEAK
BAROCLINICITY AT TAU 96, INCREASING TOWARD THE EARLY STAGES OF
FRONTOGENESIS BY TAU 120, HENCE THE SYSTEM BECOMING EXTRATROPICAL.

MODEL DISCUSSION: INCREASING UNCERTAINTY EXISTS IN THE LATER HALF
OF THE FORECAST PERIOD DUE TO A COMPETING STEERING ENVIRONMENT
DELAYING THE RECURVE, LEADING TO A WIDE SPREAD OF TAU 120 POINTS.
THE JTWC TRACK FORECAST IN THE LATER TAUS LIES NEAR THE MIDPOINTS
BETWEEN THE MULTIMODEL CONSENSUS AND THE RELIABLE AI TRACK AIDS,
WHILE THE ECMWF ENSEMBLE MEAN REMAINS THE SOLE OUTLIER TO THE
DISTANT WEST AFTER TAU 48. THE INTENSITY AIDS ARE IN BETTER
AGREEMENT THAT THE SYSTEM IS AT OR NEAR ITS PEAK WITH A GRADUAL
DECLINE GOING FORWARD AFTER TAU 24 AND A STEADY INTENSITY BETWEEN
TAU 96 AND TAU 120 DUE TO EXTRATROPICAL TRANSITION ACCELERATING THE
SYSTEM.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 00-72 HR: HIGH
   INTENSITY 72-120 HR: MEDIUM//
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