WDXS33 PGTW 110900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (TALIAH) WARNING 
NR 021//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.6S 92.1E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 315 NM WEST-SOUTHWEST OF THE COCOS ISLANDS
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 02 KTS
   SIGNIFICANT WAVE HEIGHT: 21 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
CYCLONE 14S (TALIAH) WITH CONVECTIVE BANDING LOOSELY WRAPPING INTO
THE LOW-LEVEL CIRCULATION CENTER (LLCC). THE SYSTEM REMAINS LARGE
AND HAS YET TO FURTHER CONSOLIDATE. ENVIRONMENTAL ANALYSIS
INDICATES THAT 14S IS IN A MARGINALLY FAVORABLE ENVIRONMENT
CHARACTERIZED BY MODERATE RADIAL OUTFLOW ALOFT, MODERATE (15-20
KTS) VERTICAL WIND SHEAR, AND WARM (27-28 C) SEA SURFACE
TEMPERATURES. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE LLCC BRIEFLY BECOMING EXPOSED IN THE ANIMATED MSI.
THE INITIAL INTENSITY OF 55 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON THE AGENCY DVORAK AND OBJECTIVE INTENSITY ESTIMATES LISTED
BELOW. ADDITIONALLY, A 102314Z RCM-1 SAR IMAGE REVEALED A 55-60
KNOT WIND FIELD, FURTHER SUPPORTING THE INITIAL INTENSITY.

INITIAL WIND RADII BASIS: PERSISTENCE FROM THE MENTIONED SAR DATA.

CURRENT STEERING MECHANISM: NORTHWESTERN PERIPHERY OF A BUILDING
SUBTROPICAL RIDGE POSITIONED TO THE SOUTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   KNES: T3.5 - 55 KTS
   DEMS: T3.5 - 55 KTS
   APRF: T3.0 - 45 KTS
   CIMSS SATCON: 61 KTS AT 110700Z
   CIMSS ADT: 47 KTS AT 110600Z
   CIMSS DPRINT: 54 KTS AT 110600Z
   CIMSS DMINT: 56 KTS AT 110719Z

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

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: EXTRATROPICAL TRANSITION IS NO LONGER
FORECAST TO OCCUR DURING THE FORECAST PERIOD.

FORECAST DISCUSSION: 14S IS FORECAST TO TRACK SOUTHWESTWARD, ALONG
THE STR TO THE SOUTHEAST THROUGH TAU 72. NEAR TAU 72, RIDGING
BEGINS TO BUILD IN TO THE SOUTH OF THE SYSTEM, DRIVING IT FURTHER
WESTWARD. REGARDING INTENSITY, 14S IS FORECAST TO MARGINALLY
INTENSIFY TO 65 KTS AT TAU 24 DUE TO LESSENED VERTICAL WIND SHEAR
AND SEA SURFACE TEMPERATURES REMAINING CONDUCIVE. SEA SURFACE
TEMPERATURES DROP BELOW 26 C NEAR TAU 48, AND DRY AIR BEGINS TO
ENTRAIN INTO THE VORTEX, INITIATING A WEAKENING TREND. AN INTENSITY
OF 45 KTS IS FORECAST FOR TAU 120 IN RESPONSE TO THE DEGRADING
ENVIRONMENT.  

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT
REGARDING THE TRACK OF 14S WITH A 95 NM CROSS-TRACK SPREAD AT TAU
72. SPREAD BEGINS TO INCREASE AFTER TAU 72 TO 265 NM AT TAU 120. AS
A RESULT, THE JTWC TRACK FORECAST IS PLACED WITH HIGH CONFIDENCE
THROUGH TAU 72 AND MEDIUM CONFIDENCE THEREAFTER. INTENSITY GUIDANCE
IS IN SLIGHTLY WORSE AGREEMENT, DUE PRIMARILY TO FRIA (AN RI AID)
CONTINUING TO TRIGGER, CONFLICTING WITH THE REMAINDER OF GUIDANCE.
THE OTHER AIDS INDICATE ONLY MARGINAL INTENSIFICATION OVER THE NEXT
36 HOURS. THE JTWC INTENSITY FORECAST IS PLACED SLIGHTLY HIGHER
THAN CONSENSUS TO ACCOUNT FOR THE RI POSSIBILITY.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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