WDXS31 PGTW 232100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05S (FINA) WARNING NR 
023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.9S 128.5E
   INITIAL INTENSITY: 105 KTS
   GEOGRAPHIC REFERENCE: 163 NM WEST-SOUTHWEST OF DARWIN, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 32 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
AFTER AN INITIAL STRUGGLE WITH DRY AIR ENTRAINMENT TROPICAL CYCLONE
(TC) 05S (FINA) HAS BEEN ABLE TO CONSOLIDATE AND CONTRACT OVER THE
PAST 6 HOURS GIVING THE SYSTEM AN INTENSITY OF 105 KNOTS AS IT
CONTINUES ITS SOUTHWESTWARD TRACK ACROSS THE JOSEPH BONAPARTE GULF.
CLOUD TOP TEMPERATURES ALONG THE OUTER EDGES OF THE CIRCULATION HAVE
WARMED SOMEWHAT BUT THE CENTER IS RIPE WITH DEEP CONVECTION
PERSISTING AROUND THE STILL WELL-DEFINED PINHOLE EYE AS DEPICTED BY
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY. THE ENVIRONMENT
REMAINS FAVORABLE WITH WARM SEA SURFACE TEMPERATURES (30 C TO 31
C), LOW VERTICAL WIND SHEAR (5-10 KNOTS), AND STRONG RADIAL
OUTFLOW. THE ONLY ADVERSE FACTOR IS DRY AIR SURROUNDING TC FINA,
WHICH THE SYSTEM HAS BEEN RELATIVELY RESISTANT TO THUS FAR, AND ITS
PROXIMITY TO LAND FEATURES. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON EIR IMAGERY OF THE EYE FEATURE AND AGENCY
FIXES. THE INITIAL INTENSITY OF 105 KTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES
RANGING FROM 90 TO 110 KNOTS.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   CIMSS SATCON: 99 KTS AT 231930Z
   CIMSS ADT: 99 KTS AT 231930Z
   CIMSS AIDT: 100 KTS AT 231730Z
   CIMSS D-MINT: 110 KTS AT 231814Z
   CIMSS D-PRINT: 115 KTS AT 231830Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG RADIAL

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: TROPICAL CYCLONE 05S WILL CONTINUE ON ITS
SOUTHWESTWARD TRACK THROUGH TAU 12 WITH A STEADY WEAKENING TREND
FACILITATED BY DRY AIR ENTRAINMENT. LANDFALL IS EXPECTED BETWEEN
TAU 12 AND TAU 24 COINCIDING WITH A STEEPER WEAKENING ENHANCED BY
TOPOGRAPHIC INTERACTION. THE SYSTEM IS FORECAST TO DISSIPATE OVER
LAND BY TAU 48.

MODEL DISCUSSION: CROSS TRACK SPREAD AMONG MODEL GUIDANCE IS UNDER
40 NM UNTIL LANDFALL WITH GFS MAINTAINING A NORTHERN SKIRTING OF
THE NORTH AUSTRALIAN COAST AND INTERPOLATED ECMWF AND NAVGEM
PUSHING THE SYSTEM FURTHER SOUTH AND INLAND. THE JTWC FORECAST
TRACK IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH MEDIUM
CONFIDENCE DUE TO EXPECTED TOPOGRAPHIC INFLUENCE. INTENSITY
GUIDANCE HAS A MAXIMUM SPREAD OF 25 KNOTS THROUGH THE FORECAST
PERIOD WITH ALL GUIDANCE CONCURRING ON SOME WEAKENING TILL TAU 12
AND A MUCH STEEPER WEAKENING TREND AFTER DUE TO TOPOGRAPHY AND DRY
AIR. THE JTWC OFFICIAL FORECAST REFLECTS INTENSITIES CLOSE TO THE
MULTI-MODEL CONSENSUS WITH MEDIUM CONFIDENCE. 

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   INTENSITY 00-72 HR: MEDIUM//
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