WDPS31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 23P (FILI) WARNING NR 
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.5S 161.5E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 337 NM NORTHWEST OF NOUMEA, NEW CALEDONIA
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHEASTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
MEDIUM-SIZED SYSTEM THAT HAS MOSTLY MAINTAINED A NW-SE ELONGATED
SHAPE DUE TO NORTHWESTERLY SHEAR, PARTLY EXPOSING THE LOW LEVEL
CIRCULATION (LLC). THE INITIAL POSITION AND INTENSITY ARE PLACED 
WITH HIGH CONFIDENCE BASED ON A WELL DEFINED LLC IN THE 0511128Z 
ASCAT BULLSEYE PASS. THE INTENSITY IS ALSO SUPPORTED BY AGENCY AND
AUTOMATED DVORAK ESTIMATES (SEE BELOW). ANALYSIS INDICATES A 
MARGINALLY FAVORABLE ENVIRONMENT WITH MODERATE TO STRONG VWS OFFSET 
BY STRONG POLEWARD OUTFLOW AND WARM SST. THE CYCLONE IS TRACKING 
ALONG THE WESTERN PERIPHERY OF THE STR TO THE EAST.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA.

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   PHFO: T3.0 - 45 KTS
   CIMSS SATCON: 48 KTS AT 050917Z
   CIMSS ADT: 41 KTS AT 051140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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: TC FILI WILL CONTINUE ON ITS CURRENT TRACK
UNDER THE STEERING INFLUENCE OF THE STR. THE MARGINALLY FAVORABLE
ENVIRONMENT WILL PREVAIL UP TO TAU 36, PEAKING THE INTENSITY TO
65KTS. AFTERWARD, INCREASING VWS AND COOLING SST WILL GRADUALLY
ERODE THE SYSTEM DOWN TO 50KTS BY TAU 72. CONCURRENTLY BY TAU 48,
TC 23P WILL BEGIN SUBTROPICAL TRANSITION AND BY TAU 72, WILL
TRANSFORM INTO A SUBTROPICAL SYSTEM WITH AN EXPANDING WIND FIELD. 


MODEL DISCUSSION: NUMERICAL MODELS ARE IN GENERAL AGREEMENT TO A
POLEWARD TRACK WITH A GRADUAL SPREAD TO 292NM BY TAU 72. NAVGEM IS
THE NOTABLE RIGHT-OF-TRACK OUTLIER AND UKMET IS ON THE LEFT MARGIN.
THERE IS MEDIUM CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID
JUST TO THE LEFT OF THE MODEL CONSENSUS TO OFFSET A MORE UNLIKELY
NAVGEM TRACK SOLUTION.  

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