WDXS31 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (DUDZAI) WARNING 
NR 006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.3S 78.0E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 692 NM SOUTH-SOUTHEAST OF DIEGO GARCIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 01 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL CYCLONE (TC) 14S (DUDZAI) HAS WEAKENED OVER THE PAST
TWELVE HOURS WITH A CONTRACTING MASS OF DEEP CONVECTIVE ACTIVITY,
WARMING CLOUD TOP TEMPERATURES, AND AN EYE FEATURE STRUGGLING TO
MAINTAIN SHAPE AS DEPICTED BY ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY AND MULTISPECTRAL SATELLITE IMAGERY (MSI). THE
SYSTEM HAS BECOME QUASI-STATIONARY AS THE INFLUENCE OF THE
SUBTROPICAL RIDGING PATTERN TO THE SOUTH HAS WEAKENED SLIGHTLY. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE
EVIDENT EYE-FEATURE OBSERVED ON  THE AFOREMENTIONED MSI. THE
INITIAL INTENSITY OF 100 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED
ON 130029Z SAR DATA, CIMSS OBJECTIVE INTENSITY ESTIMATES, AND
AGENCY SUBJECTIVE ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: 130029Z SAR DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGING (STR) TO THE SOUTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   DEMS: T5.5 - 102 KTS
   FMEE: T5.5 - 102 KTS
   FIMP: T6.0 - 115 KTS
   CIMSS SATCON: 115 KTS AT 130130Z
   CIMSS ADT: 97 KTS AT 130600Z
   CIMSS AIDT: 96 KTS AT 130600Z
   CIMSS D-MINT: 116 KTS AT 130129Z
   CIMSS D-PRINT: 99 KTS AT 130600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE POLEWARD

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 DUDZAI IS EXPECTED TO TRACK WESTWARD INTO
TAU 72, THEN SOUTHWEST INTO TAU 120, SLOWLY GAINING SPEED OVER
WATER AS THE INFLUENCE OF THE SUBTROPICAL RIDGE TO THE SOUTH BUILDS
WESTWARD. THE SYSTEM IS FORECASTED TO WEAKEN STEADILY UNTIL TAU 48
FROM PROLONGED EXPOSURE TO MODERATE SHEAR (ABOVE 15 KTS) AND DRY
AIR WRAPPING INTO THE VORTEX FROM THE SOUTHWEST. BETWEEN TAU 48 AND
TAU 96, TC DUDZAI WILL HAVE SOME TIME TO REGAIN INTENSITY, DUE TO A
FORECASTED INCREASE POLEWARD OUTFLOW ALOFT. AFTER TAU 96 THE
CIRCULATION WILL RESUME A WEAKENING TREND, BECOMING TOO INHIBITED
BY EXCESSIVE VERTICAL WIND SHEAR AND DRY AIR ENTRAINMENT. 

MODEL DISCUSSION: THE MAJORITY OF MODEL GUIDANCE IS WITHIN A 75 NM
CROSS TRACK SPREAD, WITH THE EXCEPTION OF NAVGEM, WHICH TAKES A
DRAMATICALLY SHARP SOUTHWARD TURN AFTER TAU 36. THE JTWC FORECASTED
TRACK IS PLACED CLOSE TO THE MULTI MODEL CONSENSUS WITHOUT THE
INFLUENCE OF NAVGEM. INTENSITY GUIDANCE IS MORE SPREAD (UP TO 70
KTS AT TAU 60) WITH HWRF AND HAFS-A DEPICTING A GREATER AMOUNT AND
LONGER PERIOD OF INTENSIFICATION AFTER TAU 48. THE JTWC OFFICIAL
FORECAST REFLECTS VALUES SLIGHTLY ABOVE THE JTWC MULTI MODEL
CONSENSUS, ESPECIALLY AFTER TAU 60 ACCOUNTING FOR UNCERTAINTY IN
THE  MODELS DEPICTING HOW MUCH ADVANTAGEOUS OUTFLOW WILL HELP TC
DUDZAI COMBAT SHEAR AND DRY AIR.

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