WDPN32 PGTW 301500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 23W (KONG-REY) WARNING NR 023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.4N 123.6E
   INITIAL INTENSITY: 120 KTS
   GEOGRAPHIC REFERENCE: 305 NM SOUTH-SOUTHEAST OF TAIPEI, TAIWAN
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 23W (KONG-REY) HAS PEAKED IN INTENSITY AND IS NOW
WEAKENING DUE TO AN EYEWALL REPLACEMENT CYCLE (ERC). ANIMATED
ENHANCED INFRARED (EIR) SATELLITE IMAGERY PRESENTS A COMPLETELY
DIFFERENT LOOKING TY KONG-REY AS COMPARED TO SIX TO TWELVE HOURS
AGO. CLOUD TOPS CONTINUE TO WARM, AT LEAST A FURTHER 10C SINCE
300600Z. CONVECTION HAS BECOME MORE FRAGMENTED AND THE COLDEST
CLOUD TOPS NO LONGER FORM A FULLY COMPOSED EYEWALL IN THE EIR. A
300904Z WSF-M COLOR ENHANCED 89GHZ MICROWAVE IMAGE REVEALED A
TEXTBOOK DOUBLE-EYEWALL CONFIGURATION, WITH A SYMMETRICAL,
APPROXIMATELY 30NM DIAMETER INNER EYEWALL SURROUNDED BY A MOAT OF
DRY AIR AND A SECONDARY EYEWALL OF 150NM DIAMETER. THE SYSTEM HAS
NOW MOVED INTO RANGE OF THE TAIWAN RADAR NETWORK, AND ALSO SHOWS A
CLEAR DOUBLE EYEWALL CONFIGURATION AND SUPPORTS THE INITIAL
POSITION WITH HIGH CONFIDENCE. A 300944Z RCM-2 SAR BULLSEYE
REVEALED A 118 KNOT MAXIMUM WINDS IN THE INNER EYEWALL WITH A
RADIUS OF MAXIMUM WINDS (RMW) OF APPROXIMATELY 25NM. THE INITIAL
INTENSITY IS THUS SET AT 120 KNOTS, WHICH IS ALSO SUPPORTED BY A
BLEND OF THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES NOTED
BELOW. AGENCY FIX FINAL-T NUMBERS AS WELL AS THE ADT RAW-T CONTINUE
TO DROP PRECIPITOUSLY, WITH SEVERAL DOWN TO THE T5.5 RANGE, AS THE
CLOUD TOPS CONTINUE TO WARM AND DECREASE IN AREAL COVERAGE. WITH
THE EXCEPTION OF THE ONGOING ERC, THE ENVIRONMENT REMAINS
FAVORABLE, WITH LOW VWS, WARM SSTS AND GOOD POLEWARD AND
EQUATORWARD OUTFLOW CHANNELS ENHANCING THE ALREADY STRONG RADIAL
OUTFLOW.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) CENTERED TO THE EAST-NORTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T7.0 - 140 KTS 
   RJTD: T6.5 - 127 KTS
   RCTP: T6.5 - 127 KTS
   KNES: T6.5 - 127 KTS
   CIMSS SATCON: 130 KTS AT 301056Z
   CIMSS ADT: 113 KTS AT 301200Z
   CIMSS AIDT: 121 KTS AT 301200Z
   CIMSS DPRINT: 126 KTS AT 301300Z
   CIMSS DMINT: 132 KTS AT 300928Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD
   OTHER FACTORS: ERC. 

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: TY 23W CONTINUES TO TRUCK ALONG ON A STEADY
NORTHWESTWARD HEADING, AT ABOUT 8-10 KNOTS, SOMEWHAT SURPRISINGLY
NOT SHOWING MUCH WOBBLE FOR THE MOMENT. AS THE SYSTEM APPROACHES
TAIWAN THIS IS LIKELY TO CHANGE, WITH UNPREDICTABLE AND ERRATIC
TRACK MOTION EXPECTED AFTER TAU 12, ESPECIALLY AS THE OUTER
SECONDARY EYEWALL BEGINS TO REACH THE COASTLINE. TY 23W IS EXPECTED
TO WEAKEN STEADILY FROM NOW UNTIL LANDFALL, WHICH IS EXPECTED
WITHIN THE NEXT 18 HOURS AS IT SUCCUMBS TO THE EFFECTS OF THE
ONGOING ERC. DUE TO AN EXTREMELY LARGE EYE PRESENT AT THE START OF THE
ERC, AND THE LIMITED TIME REMAINING BEFORE LANDFALL, IT IS UNLIKELY
THAT THE ERC WILL FULLY COMPLETE AND THE SYSTEM IS NOT LIKELY TO
REINTENSIFY PRIOR TO LANDFALL. HOWEVER, THE WIND FIELD WILL
INCREASE IN SIZE DURING THE ERC, PUTTING A MUCH LARGER PORTION OF
TAIWAN UNDER THREAT OF DESTRUCTIVE WINDS. THE FORECAST TAKES THE
CENTER OF TY 23W OVER THE HIGHEST PEAKS OF THE CENTRAL MOUNTAIN
RANGE (CMR) BY TAU 24, AND THE SYSTEM IS VERY LIKELY TO DECOUPLE AS
IT CROSS THE CMR, WITH A MID-LEVEL VORTEX JUMPING THE MOUNTAIN
RANGE AND REFORMING FROM THE TOP DOWN ON THE WESTERN SIDE OF
TAIWAN. BETWEEN TAU 24 AND TAU 36, THE VORTEX WILL MOVE INTO THE
TAIWAN STRAIT AND START TO ROUND THE RIDGE AXIS, QUICKLY TURNING TO
A NORTHWARD TRACK. SKIRTING THE EAST COAST OF CHINA BETWEEN TAU 36
AND TAU 48, THE SYSTEM TURNS NORTHEASTWARD AND ACCELERATES,
TRAVELING ALONG A DEVELOPING FRONTAL SYSTEM DRAPED ACROSS THE EAST
CHINA SEA (ECS) AND SOUTH OF JAPAN. AS THE SYSTEM MOVES INTO THE
ECS IT BEGINS EXTRATROPICAL TRANSITION (ETT) AS IT IS PICKED UP BY
A 500MB SHORTWAVE TROF AND STARTS TO INTERACT WITH A 200MB JET
STREAK. THE TRANSITIONING SYSTEM WILL RAPIDLY CROSS THE ECS AND BE
APPROACHING KYUSHU BY TAU 72, WHILE STEADILY WEAKENING. AT THIS
POINT THE SYSTEM COULD ALREADY BE FULLY EXTRATROPICAL, BUT THE
TRANSITION PHASE MAY TAKE A BIT LONGER AND THUS THE FORECAST IS
EXTENDED OUT TO TAU 96. AS THE SYSTEM PASSES THE JAPANESE ISLANDS
TO THE SOUTH, THE STRONGEST WINDS ARE GOING TO BE NORTHERLY WINDS
STREAMING THROUGH THE MOUNTAIN PASSES AND CHANNELS BETWEEN THE
ISLANDS ON THE BACKSIDE OF THE SYSTEM.   

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE REMAINS IN VERY GOOD
AGREEMENT THROUGH TAU 48, WITH MINIMAL CROSS- OR ALONG-TRACK
SPREAD. CROSS-TRACK SPREAD INCREASES TO 150NM AND ALONG-TRACK
SPREAD INCREASES TO 520NM BY TAU 72 AS THE MODELS DISAGREE ON THE
STRENGTH AND DEPTH OF THE VORTEX AND THUS ON HOW QUICKLY IT WILL
TRANSIT NORTHEASTWARD. ALONG-TRACK SPREAD INCREASES TO OVER 1000NM
BY TAU 96. THE JTWC FORECAST IS SET CLOSE TO THE CONSENSUS MEAN
THROUGH THE ENTIRE FORECAST, WITH HIGH CONFIDENCE TO TAU 72 AND LOW
THEREAFTER. INTENSITY GUIDANCE IS ALSO IN GOOD AGREEMENT, AND THE
JTWC FORECAST IS PLACED ON TOP OF THE HWRF TRACKER.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
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