WDXS33 PGTW 150900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (TALIAH) WARNING 
NR 029//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 25.2S 83.5E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 1088 NM SOUTHWEST OF THE COCOS ISLANDS
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 21 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS SHEARED
CONVECTION PERSISTING TO THE SOUTH OF AN EXPOSED LOW-LEVEL
CIRCULATION CENTER. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON VISIBLE SATELLITE IMAGERY AND DIRECTIONAL
AMBIGUITY DATA FROM A 150258Z METOP-B ASCAT PASS. THE INITIAL
INTENSITY OF 50 KTS IS ASSESSED WITH HIGH CONFIDENCE, ABOVE AGENCY
SUBJECTIVE DVORAK AND AUTOMATED INTENSITY ESTIMATES, BASED ON WIND
SPEED DATA FROM THE 150258Z ASCAT PASS INDICATING A PATCH OF 45 TO
50 KNOT WINDS SOUTHWEST OF THE CENTER. THE SYSTEM HAS INTENSIFIED
RECENTLY DESPITE DECREASING ALONG-TRACK SEA SURFACE TEMPERATURES AND
MODERATE VERTICAL WIND SHEAR AS A PRONOUNCED POLEWARD OUTFLOW
CHANNEL AND ASSOCIATED DIFFLUENCE ALOFT ARE SUPPORTING CONVECTIVE
DEVELOPMENT OVER THE SOUTHERN PORTION OF THE CIRCULATION.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA (150258Z METOP-B ASCAT
PASS)

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) TO
THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   DEMS: T3.0 - 45 KTS
   CIMSS ADT: 34 KTS AT 150600Z
   CIMSS AIDT: 36 KTS AT 150600Z
   CIMSS D-MINT: 26 KTS AT 150633Z
   CIMSS D-PRINT: 32 KTS AT 150600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 25-30 KTS
   SST: 25-26 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: NEAR-TERM FORECAST INTENSITIES HAVE
DECREASED IN LIGHT OF THE RECENTLY OBSERVED INTENSIFICATION TREND.
OTHERWISE, THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM
THE PREVIOUS WARNING.

FORECAST DISCUSSION: TC 14S WILL TRACK SOUTHWESTWARD OVER THE NEXT
72 HOURS UNDER THE INFLUENCE OF BUILDING DEEP LAYER RIDGING TO THE
SOUTHEAST. AFTER TAU 72, THE PREVAILING STEERING FLOW WILL WEAKEN,
RESULTING IN A PERIOD OF NEARLY STATIONARY MOTION FOR THE REMNANT
CIRCULATION. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO PERSIST IN
THE NEAR-TERM, ALLOWING MAXIMUM LOW-LEVEL WIND SPEEDS TO THE SOUTH
OF THE HIGHLY ASYMMETRIC CIRCULATION TO HOVER AROUND 50 KNOTS, WITH
WEAKER GALES OBSERVABLE IN THE NORTHERN PORTION OF THE CIRCULATION.
OVER TIME, PASSAGE OVER COOLER WATER AND PERSISTENT VERY WIND SHEAR
WILL TAKE THEIR TOLL, LEADING TO DISSIPATION BY TAU 96. 

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN VERY GOOD
AGREEMENT THROUGH THE FIRST 72 HOURS OF THE FORECAST PERIOD, WITH
SPREAD INCREASING THEREAFTER AS THE SYSTEM DISSIPATES AND ENTERS A
WEAKER STEERING ENVIRONMENT. SKILLFUL INTENSITY GUIDANCE SUPPORTS
VERY SLOW WEAKENING TO DISSIPATION IN LINE WITH EXPECTED
ENVIRONMENT CONDITIONS AND PREVIOUS FORECASTS. OVERALL, THERE IS
HIGH CONFIDENCE IN THE TRACK AND INTENSITY FORECASTS THROUGH TAU
72, WITH TRACK UNCERTAINTY INCREASING A BIT THEREAFTER.

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