WDXS31 PGTW 110900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (DUDZAI) WARNING NR 
002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.0S 77.0E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 543 NM SOUTH-SOUTHEAST OF DIEGO GARCIA
   MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 18 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
CYCLONE 14S (DUDZAI) WITH CURVED DEEP CONVECTION TIGHTLY WRAPPING
INTO THE CENTER OF A HIGHLY COMPACT CIRCULATION. OUTFLOW APPEARS TO
BE IMPROVING, WITH DEFINED CIRRUS FILAMENTS NOW EXPANDING OUTWARD
IN THE WESTWARD DIRECTION FROM THE SYSTEM. THE INITIAL POSITION IS
PLACED WITH MEDIUM CONFIDENCE BASED ON THE ANIMATED MSI. THE
INITIAL INTENSITY OF 55 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON THE AGENCY DVORAK FIXES AND CIMSS OBJECTIVE INTENSITY
ESTIMATES LISTED BELOW. ENVIRONMENTAL ANALYSIS INDICATES THAT 14S
CONTINUES TO BE PLACED WITHIN A FAVORABLE ENVIRONMENT CHARACTERIZED
BY STRONG POLEWARD OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND
SHEAR, AND WARM (28-29 C) SEA SURFACE TEMPERATURES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A RIDGING
COMPLEX TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   DEMS: T3.5 - 55 KTS
   FMEE: T3.5 - 55 KTS
   CIMSS ADT: 55 KTS AT 110600Z
   CIMSS AIDT: 44 KTS AT 110600Z
   CIMSS D-MINT: 52 KTS AT 110727Z
   CIMSS D-PRINT: 61 KTS AT 110600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: INCREASED THE PEAK INTENSITY TO 85
KTS. OTHERWISE, THERE ARE NO SIGNIFICANT CHANGES.

FORECAST DISCUSSION: 14S IS FORECAST TO CONTINUE TRACKING
SOUTHEASTWARD THROUGH TAU 24. NEAR TAU 24, THE RIDGING COMPLEX TO
THE EAST IS EXPECTED TO SPLIT INTO TWO DISTINCT RIDGES. THERE WILL
END UP BEING A NEAR-EQUATORIAL RIDGE (NER) TO THE NORTH AND A
SEPARATE SUBTROPICAL RIDGE (STR) ANCHORED TO THE SOUTHEAST. THE STR
TO THE SOUTHWEST WILL BECOME THE PRIMARY STEERING MECHANISM,
CAUSING 14S TO SLOW DOWN AND MAKE A SHARP SOUTHWESTWARD TURN. NEAR
TAU 36, AN EXTENSION OF THE STR WILL BUILD TO THE SOUTH OF 14S,
CAUSING IT TO BEGIN TRACKING WESTWARD. ADDITIONALLY, THE LOW-LEVEL
STEERING INFLUENCE WILL BE DOMINATED BY THE EASTERLIES TO THE SOUTH
OF THE SYSTEM, FURTHER SUPPORTING A WESTWARD TRACK. REGARDING
INTENSITY, 14S IS FORECAST TO QUICKLY INTENSIFY OVER THE NEXT 36
HOURS AS THE ENVIRONMENT REMAINS FAVORABLE. THE PEAK INTENSITY IS
FORECAST TO BE AROUND 85 KTS BEFORE THE SYSTEM MAKES THE WESTWARD
TURN. HOWEVER, THE COMPACT NATURE OF THE SYSTEM COULD POTENTIALLY
ALLOW FOR RAPID INTENSIFICATION (RI) THROUGH THIS TIME, AND
THEREFORE, AN EVEN HIGHER PEAK. NEAR TAU 48, NORTHWESTERLY SHEAR IS
EXPECTED TO INCREASE, CAUSING 14S TO WEAKEN THROUGH THE REMAINDER
OF THE FORECAST PERIOD. 

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN MODERATE
AGREEMENT THROUGHOUT THE FORECAST PERIOD BESIDES TWO EXTREME
OUTLIERS IN GALWEM AND UKMET. THESE MODELS STALL THE SYSTEM IN
PLACE AFTER TAU 48, WHILE THE REMAINDER OF GUIDANCE COMMENCES THE
WESTWARD TURN. WITH THE EXCEPTION OF THE TWO OUTLIERS, GUIDANCE
AGREES ON THE GENERAL TRACK PHILOSOPHY BUT DIFFER IN BOTH THE
SHARPNESS AND QUICKNESS OF THE WESTWARD TURN. NAVGEM TAKES THE
SHARPEST TURN WHILE GFS TAKES THE WIDEST TURN. CROSS-TRACK SPREAD
AT TAU 72 IS AROUND 110 NM, WHICH OPENS UP TO 190 NM AT TAU 120.
THE JTWC TRACK FORECAST IS PLACED CLOSE THE MODIFIED CONSENSUS
(TAKING OUT THE TWO OUTLIERS) WITH OVERALL MEDIUM CONFIDENCE.
INTENSITY GUIDANCE IS SLIGHTLY SPLIT WITH COAMPS-TC AND GFS SHOW
ONLY MARGINAL INTENSIFICATION THROUGH TAU 48. ON THE OTHER HAND,
THE REST OF GUIDANCE CALLS FOR RAPID OR NEAR-RAPID INTENSIFICATION
THROUGH TAU 48. THE JTWC INTENSITY FORECAST FOLLOWS CLOSELY TO THE
HAFS-A WITH LOW CONFIDENCE DUE TO UNCERTAINTIES REGARDING THE PEAK
INTENSITY OF THE SYSTEM.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   TRACK 72-120 HR: MEDIUM
   INTENSITY 00-72 HR: LOW
   INTENSITY 72-120 HR: LOW//
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