WDXS32 PGTW 290900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 06S (ANGGREK) WARNING 
NR 029//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.7S 71.1E
   INITIAL INTENSITY: 105 KTS
   GEOGRAPHIC REFERENCE: 798 NM EAST-SOUTHEAST OF PORT LOUIS,
MAURITIUS
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 45 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A COMPACT
SYSTEM THAT HAS BECOME MORE ELONGATED AND ASYMMETRICAL WITH INITIAL
EXPOSURE TO THE PREVAILING WESTERLIES. TRANSVERSE BANDING IS
EVIDENT ALONG THE SOUTHERN PERIPHERIES TO INDICATE STRONG OUTFLOW
AND IMMINENT HIGH VERTICAL WIND SHEAR. ENHANCED EIR IMAGERY SHOWS
THE CENTRAL DENSE OVERCAST REMAINS DEEP BUT HAVE NOW BEGUN TO WARM
WHILE MAINTAINING A DEFINED 10-NM EYE. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE. THE INITIAL
INTENSITY IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON THE PGTW,
FIMP, AND FMEE DVORAK ESTIMATES OF T5.5 (102KTS) AND EQUIVALENT
AUTOMATED DVORAK ESTIMATES. THIS INTENSITY IS CONSISTENT WITH THE
GRADUAL 12-HR CONVECTIVE DETERIORATION. ANALYSIS INDICATES A
FAVORABLE ENVIRONMENT WITH LOW VWS, WARM SST, AND STRONG POLEWARD
OUTFLOW.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM:  DEEP LAYERED SUBTROPICAL RIDGE (STR)
TO THE SOUTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   FMEE: T5.5 - 102 KTS
   FIMP: T5.5 - 102 KTS
   CIMSS ADT: 104 KTS AT 290500Z
   CIMSS AIDT: 103 KTS AT 290500Z
   CIMSS DPRINT: 105 KTS AT 290500Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   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 ANGGREK WILL TURN MORE POLEWARD AS IT
ROUNDS THE STR AXIS, RECURVE AND ACCELERATE SOUTHEASTWARD AS THE
STR RECEDES IN RESPONSE TO AN APPROACHING MID-LATITUDE FROM THE
WEST. THE ENVIRONMENT WILL QUICKLY BECOME UNFAVORABLE WITH
INCREASING VWS ASSOCIATED WITH THE STRONG WESTERLIES, THEN THE
ADDITION OF COOLING SST AND DRY AIR INTRUSION WILL GRADUALLY ERODE
THE SYSTEM. CONCURRENTLY, BY TAU 36, TC 08S WILL ENTER THE
BAROCLINIC ZONE AND BEGIN EXTRA-TROPICAL TRANSITION (ETT), AND BY
TAU 120, WILL TRANSFORM INTO A STORM-FORCE COLD CORE LOW WITH AN
EXPANDING WIND FIELD.

MODEL DISCUSSION: NUMERICAL MODELS CONTINUE TO BE IN TIGHT
AGREEMENT WITH A GRADUAL AND EVEN SPREAD TO A MERE 98NM BY TAU 48
LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST. THERE IS ONLY
MEDIUM CONFIDENCE IN THE INTENSITY FORECAST DUE TO THE
UNCERTAINTIES ASSOCIATED WITH ETT. 

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