WDPN32 PGTW 310300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 23W (KONG-REY) WARNING NR 025//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.0N 122.2E
   INITIAL INTENSITY: 110 KTS
   GEOGRAPHIC REFERENCE: 190 NM SOUTH-SOUTHEAST OF TAIPEI, TAIWAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 54 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAGGED,
BUT RELATIVELY SYMMETRICAL EYE FEATURE OF TY 23W, AS IT COMPLETES
THE EYEWALL REPLACEMENT CYCLE (ERC), WHILE APPROACHING TAIWAN FROM
THE SOUTHEAST. THE ENVIRONMENTAL CONDITIONS CONTINUE TO BE
FAVORABLE, WITH VERY GOOD POLEWARD AND EQUATORWARD OUTFLOW, OFFSET
HOWEVER BY QUICKLY APPROACHING LAND INTERACTION. AS THE SYSTEM IS
STARTING TO PUSH AGAINST THE TAIWANESE CENTRAL MOUNTAIN RANGE
(CMR), IT CONTINUES TO WEAKEN THROUGH PRESENCE OF DRY AIR SLOT AS
WELL AS BREAKS IN MID AND UPPER LEVEL CIRCULATION. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A WELL-DEFINED EYE
FEATURE VISIBLE ON THE MSI LOOP, AS WELL AS THE 302224Z F16 SSMIS
MICROWAVE PASS ALSO SHOWING A CLEAR MICROWAVE EYE. THE INITIAL
INTENSITY OF 110 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON
AGENCY AND OBJECTIVE ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR)
CENTERED TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T6.5 - 127 KTS
   RCTP: T6.5 - 127 KTS
   KNES: T5.5 - 102 KTS
   CIMSS ADT: 102 KTS AT 302330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD
   OTHER FACTORS: COMPLETED EYEWALL REPLACEMENT CYCLE

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TYPHOON 23W IS ON ITS FINAL STRETCH BEFORE
LANDFALL OVER SOUTHEASTERN TAIWAN HAPPENING WITHIN THE NEXT COUPLE
HOURS. AS THE SYSTEM CROSSES THE CMR AND RE-EMERGES OVER THE TAIWAN
STRAIT, IT IS FORECAST TO WEAKEN TO 60-80 KTS BY TAUS 12-24 AND
THEN CONTINUE TRACKING NORTHEASTWARD UNDER THE INFLUENCE OF THE
DEEP-LAYER STR TO THE EAST. INTERACTION WITH THE RUGGED TERRAIN OF
TAIWAN MAY HOWEVER SIGNIFICANTLY IMPACT TY 23W MOTION AND CAN CAUSE
ERRATIC TRACK CHANGES. AS THE TY 23W ROUNDS THE AXIS OF THE RIDGE
IT IS EXPECTED TO BEGIN INTERACTING WITH THE BAROCLINIC ZONE AND
START EXTRATROPICAL TRANSITION (ETT) BY TAU 48. AT THAT STAGE, IT
WILL CONTINUE TO WEAKEN, DUE TO DRASTICALLY INCREASING VERTICAL
WIND SHEAR AND COOL SEA SURFACE TEMPERATURES, BUT WILL BE PICKED UP
BY A 200MB JET TOWARDS THE END OF THE FORECAST PERIOD, LEADING TO
SIGNIFICANT INCREASE IN OVER-WATER SPEED OF THE SYSTEM. TY 23W IS
FORECAST TO WEAKEN TO 40 KTS AS IT PASSES THE RYUKYU ISLANDS.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT IN
REGARDS TO TRACK AND INTENSITY, PARTICULARLY OVER THE NEXT 36 HOURS
WITH ALL TRACK AND INTENSITY GUIDANCE BEING IN TIGHT AGREEMENT, BUT
STARTS TO DEVIATE AFTERWARDS. BY TAU 72, THE CROSS-TRACK SPREAD IS
ESTIMATED AT 215 NM, WHILE ACROSS-TRACK SPREAD IS OVER 700 NM.
MODELS ARE NOT IN GOOD AGREEMENT IN REGARD TO THE INTERACTION
BETWEEN THE VORTEX AND THE BAROCLINIC ZONE, THEREFORE WATCHING THE
FOLLOWING MODEL RUNS CLOSELY WILL BE CRUCIAL TO CORRECT ASSESSMENT
OF TRACK GUIDANCE. AT THE MOMENT JTWC TRACK IS LAID CLOSE TO THE
MULTI-MODEL CONSENSUS. LONG TERM INTENSITY GUIDANCE IS IN BETTER
AGREEMENT THAN TRACK GUIDANCE, WITH ALL MODELS PREDICTING STEADY
WEAKENING OF THE SYSTEM THROUGHOUT THE 96H FORECAST PERIOD.

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