WDPN32 PGTW 290300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 23W (KONG-REY) WARNING NR 017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.4N 127.2E
   INITIAL INTENSITY: 80 KTS
   GEOGRAPHIC REFERENCE: 561 NM SOUTHEAST OF TAIPEI, TAIWAN
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 32 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TYPHOON 23W
(KONG-REY) WITH A CONTINUED IMPROVED APPEARANCE OVER THE PAST 6
HOURS. THE DEFINED BANDING HAS PERSISTED AS THE SYSTEM CONTINUES TO
BECOME MORE SYMMETRIC AND A LARGE RAGGED EYE HAS STARTED TO FORM.
WITH THE QUICKLY IMPROVED STRUCTURE OVER THE PAST 6 HOURS, RAPID
INTENSIFICATION (RI) IS ANALYZED TO BE CURRENTLY OCCURRING.
ENVIRONMENTAL ANALYSIS INDICATES THAT 23W IS IN A FAVORABLE
ENVIRONMENT FOR INTENSIFICATION CHARACTERIZED BY STRONG RADIAL
OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR, AND WARM (29-30
C) SEA SURFACE TEMPERATURES. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON THE RAGGED EYE SEEN IN THE ANIMATED MSI.
THE INITIAL INTENSITY OF 80 KTS IS ASSESSED WITH HIGH CONFIDENCE
BASED ON A 282129Z SEN1 SAR IMAGE SHOWING 80-85 KNOT WINDS IN THE
SOUTHWESTERN QUADRANT WITH SLIGHTLY LOWER (70-75 KTS) WINDS IN THE
REMAINDER OF THE QUADRANTS. THE AGENCY DVORAK AND OBJECTIVE
INTENSITY ESTIMATES LISTED BELOW ALSO AIDED IN THE PLACEMENT OF THE
INITIAL INTENSITY.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
POSITIONED TO THE EAST AND NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   RJTD: T4.5 - 77 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T5.0 - 90 KTS
   CIMSS SATCON: 86 KTS AT 290000Z
   CIMSS ADT: 77 KTS AT 290000Z
   CIMSS AIDT: 79 KTS AT 290000Z
   CIMSS DPRINT: 78 KTS AT 282330Z
   
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: 23W IS FORECAST TO CONTINUE TRACKING
NORTHWESTWARD THROUGH TAU 48 ALONG THE WESTERN PERIPHERY OF THE STR
POSITIONED TO THE EAST. 23W IS FORECAST TO MAKE LANDFALL ALONG THE
SOUTHEASTERN COAST OF TAIWAN BETWEEN TAUS 48 AND 60. NEAR TAU 72,
THE SYSTEM WILL BEGIN ROUNDING THE AXIS OF THE RIDGE AS IT ENTERS
THE TAIWAN STRAIT. AFTERWARDS 23W IS EXPECTED TO TRACK
NORTHEASTWARD THROUGH THE REMAINDER OF THE FORECAST PERIOD AS IT
ENTERS THE BAROCLINIC ZONE AND TRANSITIONS INTO AN EXTRATROPICAL
CYCLONE. REGARDING INTENSITY, 23W IS FORECAST TO RAPIDLY INTENSIFY
TO A PEAK OF 125 KTS AT TAU 36 AS THE ENVIRONMENT REMAINS HIGHLY
FAVORABLE. AS THE SYSTEM APPROACHES TAIWAN, LAND INTERACTION WILL
BEGIN TO DEGRADE THE VORTEX. AN INTENSITY OF 115 KTS IS FORECASTED
NEAR THE TIME OF LANDFALL. AFTER THE SYSTEM CROSSES TAIWAN AND
ENTERS THE TAIWAN STRAIT LAND INTERACTION WILL HAVE WEAKENED THE
VORTEX TO AROUND 65 KTS. AFTER TAU 72, VERTICAL WIND SHEAR WILL
QUICKLY RISE AND SEA SURFACE TEMPERATURES WILL COOL CAUSING 23W TO
DROP TO AROUND 45 KTS AS IT BEGINS EXTRATROPICAL TRANSITION. THE
AMOUNT OF LAND INTERACTION WITH EASTERN CHINA WILL ALSO PLAY A ROLE
IN THE STRENGTH OF THE VORTEX AS IT TRAVERSES THE EAST CHINA SEA.
EXTRATROPICAL TRANSITION IS FORECAST TO BE COMPLETE BY TAU 120 BUT
WILL LIKELY BE COMPLETE BEFORE TAU 120 AS THE SYSTEM APPROACHES
KYUSHU. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT
REGARDING THE TRACK OF 23W THROUGH TAU 72 WITH A MERE 95 NM
CROSS-TRACK SPREAD AT THAT TIME. AFTER TAU 72, ALONG TRACK SPREAD
BEGINS TO VARY DUE TO DIFFERENCES IN INTERACTION WITH THE JET AS
WELL AS INTERACTION WITH EASTERN CHINA. ECMWF DETERMINISTIC IS AN
OUTLIER, SUGGESTING A MUCH SLOWER TRACK SPEED AFTER ENTERING THE
TAIWAN STRAIT DUE TO A MORE NORTHWARD VICE NORHTEASTWARD TRACK
AFTER TAU 72 AND THEREFORE MORE LAND INTERACTION. THE JTWC TRACK
FORECAST IS PLACED CLOSER TO THE MULTI-MODEL CONSENSUS WITH A SKIRT
ALONG THE COAST OF CHINA. INTENSITY GUIDANCE IS IN MODERATE
AGREEMENT WITH PEAK INTENSITIES RANGING FROM 95 KTS TO 125 KNOTS AT
TAU 36. MODELS AGREE ON SIGNIFICANT WEAKENING AFTER TAU 48. THE
JTWC INTENSITY FORECAST IS PLACED ON THE HIGHER END OF GUIDANCE DUE
TO THE HIGHLY CONDUCIVE ENVIRONMENT AND THE QUICKLY IMPROVING
STRUCTURE WITH OVERALL MEDIUM CONFIDENCE. 

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