WDPN32 PGTW 240900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 05W (GAEMI) WARNING NR 019//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.2N 122.5E
   INITIAL INTENSITY: 125 KTS
   GEOGRAPHIC REFERENCE: 77 NM SOUTHEAST OF TAIPEI, TAIWAN
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 42 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 05W HAS RAPIDLY INTENSIFIED OVER THE PAST 24 HOURS, FROM 
90 KNOTS AT 230600Z TO THE CURRENT INTENSITY OF 125 KNOTS. ANIMATED 
ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 6 NM PINHOLE EYE, 
WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE, WITH A 
MARKED TROCHOIDAL TRACK MOTION. ANIMATED RADAR IMAGERY AND A 240512Z 
AMSR2 89 GHZ MICROWAVE IMAGE CONTINUE TO SHOW CONCENTRIC EYEWALLS 
SEPARATED BY A CLEAR MOAT FEATURE. DUE TO THE INTERACTION WITH LAND 
OVER THE PAST SIX HOURS, AN ONGOING EYEWALL REPLACEMENT CYCLE HAS 
BEEN DISRUPTED AND IS UNLIKELY TO COMPLETE. IN FACT, EIR IMAGERY AND 
CURRENT RADAR IMAGERY FROM 240600-240800Z SHOW CONVECTIVE BANDING 
FROM THE OUTER EYEWALL NOW WRAPPING INTO THE INNER EYEWALL, WITH NO 
CLEAR MOAT FEATURE AND A WEAKENING EYE. THE SYSTEM PEAKED AT 125 
KNOTS NEAR 240530Z, SUPPORTED BY THE PGTW AND DEMS SUBJECTIVE DVORAK 
ESTIMATES OF 127 KNOTS AND SEVERAL CIMSS OBJECTIVE INTENSITY 
ESTIMATES, PRIMARILY DPRINT, DMINT AND SATCON. ADT AND AIDT ESTIMATES 
CONTINUE TO REMAIN TOO LOW AT 113-115 KNOTS.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) EXTENSION TO
THE NORTH AND NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.5 - 127 KTS
   RJTD: T5.5 - 102 KTS
   KNES: T6.0 - 115 KTS
   DEMS: T6.5 - 127 KTS
   CIMSS SATCON: 137 KTS AT 240530Z
   CIMSS ADT: 115 KTS AT 240600Z
   CIMSS AIDT: 113 KTS AT 240600Z
   CIMSS DPRINT: 120 KTS AT 240700Z
   CIMSS DMINT: 128 KTS AT 240512Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 15-20 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG RADIAL
   OTHER FACTORS: LAND INTERACTION WITH EASTERN TAIWAN

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TY 05W IS MAKING LANDFALL ALONG THE RUGGED
NORTHEAST COAST OF TAIWAN AND IS BEGINNING TO WEAKEN AS MENTIONED
EARLIER. THE SYSTEM IS EXPECTED TO TRACK WEST-NORTHWESTWARD ACROSS
NORTHERN TAIWAN OVER THE NEXT 12 HOURS, WITH LIKELY DE-COUPLING OF
THE LOW-LEVEL CIRCULATION CENTER (LLCC) AND THE UPPER-LEVEL 
CIRCULATION CENTER, WHICH WILL LEAD TO RAPID WEAKENING. ADDITIONALLY, 
A LEESIDE JUMP IN THE LLCC POSITION MAY OCCUR AS THE SYSTEM EMERGES 
OVER THE TAIWAN STRAIT, WHICH IS TYPICAL OF TAIWAN-CROSSING TYPHOONS. 
AFTER TAU 12, THE SYSTEM IS EXPECTED TO BECOME VERTICALLY ALIGNED AS 
IT TRACKS ACROSS THE TAIWAN STRAIT WITH LANDFALL OVER SOUTHEAST CHINA
ANTICIPATED JUST AFTER TAU 24. AS TY 05W TRACKS INLAND, IT WILL
WEAKEN RAPIDLY AND TURN NORTHWESTWARD TOWARD A BREAK IN THE STR
ASSOCIATED WITH A SERIES OF MAJOR SHORTWAVE TROUGHS. DISSIPATION IS
EXPECTED BY TAU 72.  

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM AND JGSM, THE SOLE
OUTLIERS, DETERMINISTIC GUIDANCE IS IN FAIR AGREEMENT, WITH
INCREASING UNCERTAINTY AFTER TAU 48 DURING THE RECURVE PHASE. THE
ECMWF AND GFS ENSEMBLES (EPS AND GEFS) SUPPORT THE TRACK PHILOSOPHY, 
WITH THE LARGE MAJORITY (ALL OF THE GEFS SOLUTIONS AND GREATER THAN 
80 PERCENT OF THE EPS SOLUTIONS) OF SOLUTIONS SHOWING A RECURVE TO 
THE NORTH. RELIABLE INTENSITY GUIDANCE INCLUDING COAMPS-TC (BOTH COTC 
AND CTCX), HAFS-A AND HWRF SUPPORT THE JTWC INTENSITY FORECAST WITH 
HIGH CONFIDENCE. 

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