WDXS32 PGTW 302100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 06S (ANGGREK)
WARNING NR 032//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 30.6S 76.1E
   INITIAL INTENSITY: 90 KTS
   GEOGRAPHIC REFERENCE: 1196 NM SOUTHEAST OF PORT LOUIS, MAURITIUS
   MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 15 KTS
   SIGNIFICANT WAVE HEIGHT: 43 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THAT
TROPICAL CYCLONE (TC) 06S (ANGGREK) IS CONTINUING TO GIVE WAY TO
STRONG (40 KTS) NORTHWESTERLY VERTICAL WIND SHEAR (VWS). OVER THE
LAST TWELVE HOURS, TC 06S LOW-LEVEL CIRCULATION (LLC) HAS BECOME
DISLOCATED AND PARTIALLY EXPOSED NORTHWEST OF THE OUTFLOW SUPPORT
ALOFT, AWAY FROM THE SOUTHWESTWARD PROGRESSION OF THE UPPER-LEVEL
CONVECTIVE SUPPORT FEATURES. THE INITIAL POSITION IS ASSESSED WITH
MEDIUM CONFIDENCE DUE TO CONTINUED FLARING CONVECTION JUST
DOWNSTREAM OF THE LLC OBSCURING THE AFOREMENTIONED PARTIALLY
EXPOSED EYE FEATURE AROUND THE TIGHTEST AREA OF CYCLONIC TURNING.
THE INITIAL INTENSITY IS SET AT 90 KTS WITH MEDIUM CONFIDENCE. THE
INTENSITY IS ASSESSED FROM A 301340Z SYNTHETIC APERTURE RADAR (SAR)
IMAGE INDICATING SWATHS OF 90 KTS ALONG THE WESTERN AND EASTERN
PERIPHERIES OF THE LLCC. THE INTENSITY ESTIMATE IS EVALUATED ABOVE
THE MAJORITY OF THE OBJECTIVE AND SUBJECTIVE FIXES AS A DECREASE IN
CONVECTIVE STRUCTURES HAS MOVED DVORAK ESTIMATES LOWER THAN
OBSERVED FROM SAR AND ASCAT DATA THROUGHOUT THE LAST 12 HRS.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   DEMS: T4.5 - 77 KTS
   FIMP: T4.5 - 77 KTS
   CIMSS ADT: 59 KTS AT 301500Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 30+ KTS
   SST: 23-24 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TC 06S IS FORECAST TO CONTINUE TRACKING
SOUTHEASTWARD ALONG THE OUTER PERIPHERY OF THE SUBTROPICAL RIDGE TO
THE NORTHEAST AND TRAILING EDGE OF A STRONG FRONTAL BOUNDARY TO THE
SOUTH-SOUTHEAST. THE CYCLONE CONTINUES TO BE SHEARED APART BY 40
KTS OF NORTHWESTERLY SHEAR AND SUPPRESSED BY A DEEP LAYER OF DRY
AIR FROM THE IMMEDIATE WEST. TC PHASE SPACE DIAGRAM GUIDANCE SHOWS
TC 06S CURRENTLY TRANSITIONING INTO AN ASYMMETRIC WARM-CORE SYSTEM
THROUGH THE EXTRA-TROPICAL TRANSITION, AND EXPECTED TO BECOME
COMPLETELY EXTRA-TROPICAL BY TAU 24 AS THE SYSTEM BECOMES
SUPER-IMPOSED UNDER A WESTERLY JET MAX AND INTO MUCH COOLER SEA
SURFACE TEMPERATURES (20C) NEAR THE END OF THE FORECAST PERIOD.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN VERY GOOD
AGREEMENT ON A SOUTHEASTWARD TRACK THROUGH THE REMAINDER OF THE
FORECAST PERIOD, WITH A CROSS-TRACK SPREAD OF JUST 70NM BY TAU 24.
THE JTWC TRACK IS CONSISTENT WITH THE CONSENSUS MEAN AS TC 06S
CONTINUES THROUGH ITS EXTRA-TROPICAL TRANSITION. INTENSITY GUIDANCE
REMAINS IN MEDIUM AGREEMENT, WHILE A RAPID WEAKENING PHASE IS
FORECAST INTO TAU 24, INTENSITY GUIDANCE VARIES MODERATELY PAST TAU
12; HOWEVER, THE JTWC FORECAST IS CONSISTENT WITH THE CONSENSUS,
AND A CONTINUED RAPID DECREASE TO 50 KTS IS EXPECTED BY TAU 24.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM//
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