WDXS31 PGTW 050900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 25S (TWENTYFIVE) 
WARNING 
NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 10.8S 115.9E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 562 NM NORTHWEST OF BROOME, AUSTRALIA
   MOVEMENT PAST 6 HOURS: EASTWARD AT 26 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A HEAVILY
SHEARED TROPICAL CYCLONE (TC) 25S AS IT ACCELERATES EASTWARD UNDER
THE PRIMARY INFLUENCE OF A NEAR-EQUATORIAL RIDGE TO THE NORTH. OVER
THE LAST FEW HOURS CENTRAL CONVECTION HAS BEEN REMOVED BY THE 
EXTREMELY HIGH (35-40 KTS), EASTERLY VERTICAL WIND SHEAR (VWS), WHILE 
A PERSISTENT FLARE-UP OF CONVECTION IS STILL PRESENT TO THE WEST
OF THE FAST-PACED LOW-LEVEL CIRCULATION CENTER (LLCC). DUE TO HIGH
AND INCREASING TRANSLATIONAL SPEED, CURRENTLY ESTIMATED AT 26 KTS,
THE SPIRAL BANDS OF CONVECTION ARE SHALLOW AND POORLY ORGANIZED. 
ADDITIONAL ENVIRONMENTAL ANALYSIS REVEALS WARM (28-29 C) SEA
SURFACE TEMPERATURES (SST) AND MODERATE WESTWARD OUTFLOW, BOTH
OFFSETTING THE OTHERWISE HOSTILE CONDITIONS. STRONG WINDS ARE NEARLY
EXCLUSIVELY CONTAINED WITHIN THE NORTHWESTWARD QUADRANT DUE TO
CONVERGING GRADIENT FLOW. THE INITIAL POSITION IS PLACED WITH HIGH 
CONFIDENCE BASED ON THE FULLY EXPOSED LLCC PRESENT IN THE MSI, WHILE 
THE INITIAL INTENSITY OF 40 KTS IS ASSESSED WITH MEDIUM CONFIDENCE 
BASED ON A 050445Z OCEANSAT-3 OSCAT PASS SHOWING MAINLY 35 KTS, WITH 
SOME HIGHER VALUES PRESENT DUE TO CONVECTIVE CONTAMINATION.

INITIAL WIND RADII BASIS: 050609Z GCOMW1 AMSR2 PASS

CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) CENTERED TO
THE NORTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   CIMSS SATCON: 41 KTS AT 050551Z
   CIMSS ADT: 35 KTS AT 050530Z
   CIMSS AIDT: 34 KTS AT 050530Z
   CIMSS D-MINT: 31 KTS AT 050551Z
   CIMSS D-PRINT: 27 KTS AT 050630Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 30+ KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE WESTWARD

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 25S IS FORECAST TO TRACK SOUTHEASTWARD
UNDER THE INFLUENCE OF A NER TO THE NORTH AND ITS EXTENSION TO THE
NORTHEAST, WHILE EVENTUALLY INTERACTING WITH THE WIND FIELD OF ANOTHER
TROPICAL CYCLONE (INVEST 93S) DEVELOPING APPROXIMATELY 450 NM TO
THE SOUTHEAST. TC 25S IS EXPECTED TO CONTINUE TRACKING TOWARDS AN
EVEN MORE HOSTILE ENVIRONMENT, WITH VWS VALUES REACHING BEYOND 50
KTS. ADDITIONAL IMPACTS FROM DRY AIR ENTRAINMENT WILL ULTIMATELY
RESULT IN GRADUAL WEAKENING AND FULL DISSIPATION EXPECTED BY TAU
24.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT WITH CROSS-TRACK SPREAD OF 30 NM AT TAU 12, EXPANDING TO
A 100 NM BY THE END OF THE FORECAST. GALWEM AND UKMET ARE CURRENTLY
THE ONLY OUTLIERS CONTRIBUTING TO A SLIGHTLY INCREASED SPREAD AT
TAU 24, PROJECTING A WIDER SOUTHWARD TURN, CLOSER TO BROWSE ISLAND,
AUSTRALIA. ALL REMAINING CONSENSUS MODELS ARE ALIGNED WITHIN 30-40
NM THROUGHOUT THE CURRENT FORECAST PERIOD. IN REGARD TO INTENSITY,
ALL AVAILABLE GUIDANCE REFLECTS A STEEP WEAKENING TREND RESULTING
IN DISSIPATION WITHIN 24 HOURS.

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