WDXS31 PGTW 140900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (DUDZAI) WARNING NR 
008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.2S 77.1E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 663 NM SOUTH-SOUTHEAST OF DIEGO GARCIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 24 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
CYCLONE (TC) 14S (DUDZAI) WITH AN OBSERVABLE EYE-FEATURE THAT HAS
BECOME INCREASINGLY CLOUD-FILLED OVER THE LAST FEW HOURS. DRY AIR
IN CLOSE PROXIMITY TO THE CYCLONE IS EVIDENT, AS THE WESTERN AND
NORTHERN SEMICIRCLES HAVE REMAINED LARGELY CONVECTION FREE,
REVEALING SHALLOW CURVED CUMULIFORM LINES WRAPPING BELOW THE
RECENTLY WEAKENED SYSTEM. ROBUST POLEWARD OUTFLOW ALOFT IS ALSO
PRESENT, INDICATED BY CIRRIFORM TRANSVERSE BANDING THROUGHOUT THE
SOUTHWARD EXTENDING CHANNEL. THE ENVIRONMENT HAS BECOME MARGINALLY
FAVORABLE SINCE THE PREVIOUS WARNING (12 HOURS AGO), WITH WARM SEA
SURFACE TEMPERATURES (27-28 C), MODERATE VERTICAL WIND SHEAR (15-20
KTS), AND THE AFOREMENTIONED SUPPORTIVE UPPER-LEVEL OUTFLOW CHANNEL. 
THE PRESENT DRY AIR REMAINS A LIMITING FACTOR, WRAPPING CYCLONICALLY
FROM THE SOUTHERN QUADRANT, AROUND THE SYSTEMS WESTERN FLANK AND
INTO THE NORTHERN SEMICIRCLE. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON THE EYE-FEATURE OBSERVED ON ANIMATED MSI.
THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON
EARLIER 140023Z SENTINEL-1C SAR DATA AND SUBJECTIVE AGENCY
ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: COMBINATION OF SCATTEROMETER AND SAR DATA

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTH AND
EXTENDING TOWARD THE NORTHEAST, EAST OF TROPICAL CYCLONE 14S

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   DEMS: T4.0 - 65 KTS
   FMEE: T4.5 - 77 KTS
   CIMSS SATCON: 74 KTS AT 140300Z
   CIMSS ADT: 87 KTS AT 140600Z
   CIMSS AIDT: 86 KTS AT 140600Z
   CIMSS D-MINT: 64 KTS AT 140652Z
   CIMSS D-PRINT: 67 KTS AT 140600Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   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 14S IS FORECASTED TO CONTINUE ON A WESTWARD
TRACK OVER THE NEXT 48 HOURS ALONG THE NORTHERN PERIPHERY OF THE
SUBTROPICAL RIDGE LOCATED TO THE SOUTH. AFTER TAU 48, THE
SUBTROPICAL RIDGE TO THE SOUTH IS EXPECTED TO WEAKEN AND REPOSITION
TOWARD A SOUTHWEST TO NORTHEAST ORIENTATION. AS THE SUBTROPICAL 
WEAKENS AND REORIENTS, THE REMAINDER OF THE FORECASTED TRACK WILL 
BECOME SOUTHWESTWARD UNTIL THE END OF THE FORECAST PERIOD 
(TAU 120). REGARDING INTENSITY, TC 14S IS EXPECTED TO MAINTAIN 
INTENSITY NEAR 65 KTS OVER THE NEXT 12 TO 24 HOURS WITH SUPPORTIVE 
OUTFLOW ALOFT COMPETING AGAINST MODERATE VERTICAL WIND SHEAR BETWEEN 
15-20 KTS. AFTER TAU 24, RE-INTENSIFICATION TO 80 KTS IS FORECASTED AS 
AN EASTWARD PROGRESSING LONGWAVE TROUGH TO THE SOUTH AMPLIFIES THE
POLEWARD OUTFLOW MECHANISM UNTIL TAU 48. FOLLOWING TAU 48, DRY AIR
ENTRAINMENT WILL BEGIN TO ERODE THE SYSTEM TOWARD 50 KTS BY TAU
120. PRIOR TO TAU 120, THE SYSTEM WILL ALSO BEGIN TO EXPERIENCE
RELATIVELY COOLER SEA SURFACE TEMPERATURES AT 26 C, FURTHER
LIMITING RE-INTENSIFICATION AND CONTINUE AN EXPECTED WEAKENING PHASE.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT THROUGHOUT THE ENTIRETY OF THE FORECAST PERIOD, WITH THE
EXCEPTION OF TWO OUTLIERS, BEING NAVGEM AND GALWEM. NAVGEM
ILLUSTRATES A SOUTHWESTWARD TRACK NEAR TAU 36, 12-24 HOURS PRIOR TO
THE JTWC FORECAST TRACK. GALWEM CHARACTERIZES A NORTHWESTERLY TRACK
AFTER TAU 36, AND EVENTUALLY NORTHEAST UNTIL DISSIPATION. THE JTWC
FORECAST TRACK IS ALIGNED CLOSELY TO THE JTWC MULTI-MODEL CONSENSUS,
WITH BOTH NAVGEM AND GALWEM OMITTED. WITH THAT BEING SAID, THE
CROSS-TRACK SPREAD AT TAU 72 IS 95 NM, INCREASING TO JUST 112 NM BY
TAU 120, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK.
REGARDING INTENSITY, SUSTAINED INTENSITIES ARE AGREED UPON AMONGST
THE MAJORITY OF JTWC INTENSITY CONSENSUS SOLUTIONS OVER THE NEXT 12
TO 24 HOURS. AFTER TAU 24, MOST INTENSITY GUIDANCE ILLUSTRATES
SLIGHT RE-INTENSIFICATION UNTIL TAU 48, WITH THE EXCEPTION OF HAFS
AND COAMPS-TC. HAFS SHOWS A GREATER PERIOD OF INTENSIFICATION
TOWARD A MAXIMUM OF 105 KTS, WHILE COAMPS-TC DEPICTS STEADY
WEAKENING THROUGHOUT THE REMAINDER OF THE FORECAST. THEREFORE, 
THE JTWC INTENSITY FORECAST HAS BEEN ASSESSED WITH MEDIUM 
CONFIDENCE UNTIL TAU 120, AND IS ALIGNED JUST ABOVE THE JTWC 
MULTI-MODEL CONSENSUS.

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