WDXS31 PGTW 180300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (DUDZAI) WARNING NR 
016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.9S 66.5E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 525 NM EAST OF PORT LOUIS, MAURITIUS
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 26 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES TROPICAL
CYCLONE (TC) 14S (DUDZAI), WITH PULSING CONVECTION ONCE AGAIN
ASSOCIATED WITH A QUITE IMPRESSIVE CENTRAL DENSE OVERCAST (CDO)
FEATURE. THE LOW-LEVEL CIRCULATION CENTER (LLCC) IS NOW FULLY
OBSCURED, WHILE LOW TO MODERATE NORTHWESTERLY VERTICAL WIND SHEAR
(VWS) REMAINS APPARENT. A SIGNIFICANT INTRUSION OF A DRY AIR CAN BE
OBSERVED ADVECTING INTO THE NORTHERN SEMICIRCLE OF THE VORTEX. WHILE
THE LLCC REMAINS INDISTINCT WITHIN THE OVERALL CLOUD MASS,
LOW-LEVEL INFLOW BANDING IS DISCERNIBLE BENEATH THE MAIN CONVECTIVE
CANOPY, PROVIDING A TRACER FOR THE CIRCULATION. ALOFT, THE POLEWARD
OUTFLOW CHANNEL REMAINS ROBUST RESULTING IN SLIGHT INTENSIFICATION
OVER THE LAST FEW HOURS. THE SYNOPTIC ENVIRONMENT HAS BECOME VERY
MARGINALLY FAVORABLE, WITH IMPROVED POLEWARD OUTFLOW, WARM (27-28
C) SEA SURFACE TEMPERATURES (SST) AND SLIGHTLY REDUCED VWS. THE
INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON ANIMATED
VISIBLE IMAGERY AND EXTRAPOLATION FROM A 172103Z AMSR2 MICROWAVE
PASS. THE INITIAL INTENSITY ASSESSMENT OF MEDIUM CONFIDENCE IS
DERIVED FROM A SYNTHESIS OF SUBJECTIVE AGENCY ESTIMATES AND THE
OBJECTIVE GUIDANCE LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) CENTERED TO THE
SOUTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   DEMS: T4.0 - 65 KTS
   FMEE: T4.0 - 65 KTS
   FIMP: T3.5 - 55 KTS
   CIMSS SATCON: 56 KTS AT 180000Z
   CIMSS ADT: 74 KTS AT 180000Z
   CIMSS AIDT: 79 KTS AT 180100Z
   CIMSS D-MINT: 48 KTS AT 172103Z
   CIMSS D-PRINT: 52 KTS AT 180000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: TC 14S IS PROJECTED TO MAINTAIN A GENERALLY
SOUTHWESTWARD TRAJECTORY THROUGH THE NEXT 48 HOURS,
CIRCUMNAVIGATING THE NORTHWESTERN AND WESTERN FLANK OF THE DOMINANT
STR POSITIONED TO THE SOUTH. SUBSEQUENT TO TAU 48, UPON REACHING
THE RIDGE AXIS, TC 14S IS ANTICIPATED TO RECURVE ONTO A FINAL
EAST-SOUTHEASTWARD VECTOR, A HEADING IT WILL MAINTAIN UNTIL THE
COMPLETION OF EXTRATROPICAL TRANSITION BY TAU 96. DURING THIS
LATTER PERIOD, AN EASTWARD-PROGRESSING MID-LATITUDE TROUGH WILL
BEGIN TO INTERACT WITH THE CYCLONE, FACILITATING ITS BAROCLINIC
TRANSFORMATION AND SIGNIFICANTLY ACCELERATING ITS POLEWARD MOTION.
REGARDING INTENSITY, TC 14S IS EXPECTED TO MAINTAIN INTENSITY
AROUND 55-60 KTS OVER THE NEXT 48-72 HOURS, AS THE INNER CORE
TEMPORARILY REMAINS SHIELDED FROM THE DRIEST AIR AND ROBUST OUTFLOW
CHANNEL REMAINS IN PLACE. BEYOND TAU 72, A MORE CONSISTENT
WEAKENING TREND IS FORECAST AS SSTS FALL SHARPLY BELOW 26 C, VWS
INCREASES, AND DRY AIR INTRUSION FULLY DECOUPLES THE VORTEX. THE
EXTRATROPICAL TRANSITION PROCESS WILL OCCUR CONCURRENTLY WITH THE
SOUTHWARD TRACK INTO THE MID-LATITUDE WESTERLIES BETWEEN TAU 72 AND
TAU 96. BY TAU 96, AS TC 14S BECOMES FULLY EMBEDDED WITHIN THE
INFLUENCE OF THE AFOREMENTIONED TROUGH, INTENSITY DECAY WILL
CONTINUE, CULMINATING IN THE COMPLETION OF EXTRATROPICAL TRANSITION
BY THE END OF THE FORECAST PERIOD.

MODEL DISCUSSION: A HIGH DEGREE OF CONSENSUS EXISTS AMONG THE
NUMERICAL MODEL TRACK GUIDANCE SUITE, WITH NAVGEM BEING THE ONLY
SIGNIFICANT OUTLIER, DEPICTING A MORE WESTWARD SOLUTION DURING BOTH
INITIAL PHASE AND THE RECURVATURE PHASE NEAR TAU 72. LATERAL TRACK
UNCERTAINTY IS LOW IN THE SHORT TERM, WITH A CROSS-TRACK SPREAD OF
ONLY 60 NM AT TAU 72 (EXCLUDING NAVGEM), INCREASING TO 180 NM BY
TAU 96 DURING THE EXTRATROPICAL TRANSITION PHASE. UNCERTAINTY IN
FORWARD PROPAGATION SPEED, DIVERGES RAPIDLY AFTER TAU 72 AS THE
SYSTEM ACCELERATES POLEWARD, INCREASING TO 650 NM BY TAU 96. THE
JTWC TRACK FORECAST IS ALIGNED CLOSELY WITH THE MULTI-MODEL
CONSENSUS THROUGHOUT THE FORECAST PERIOD, LENDING MEDIUM CONFIDENCE
TO THE LONG-TERM TRACK FORECAST. WITH RESPECT TO INTENSITY, THE
GUIDANCE SUITE DEPICTS A NARROW ENVELOPE OF SOLUTIONS, INDICATING A
PERIOD OF STATIC INTENSITY THROUGH 72 HOURS, FOLLOWED BY STEADY
WEAKENING. THIS PROVIDES MEDIUM CONFIDENCE IN THE JTWC INTENSITY
FORECAST.

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