WDXS33 PGTW 092100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (TALIAH) WARNING NR 
018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.9S 93.3E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 265 NM SOUTHWEST OF THE COCOS ISLANDS
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A
PERSISTENT, BUT ELONGATED CONVECTION FULLY OBSCURING THE LOW-LEVEL
CIRCULATION CENTER OF TROPICAL CYCLONE (TC) 14S (TALIAH). THE SYSTEM 
IS EXPERIENCING WEAK TO MODERATE, EASTERLY VERTICAL WIND SHEAR (VWS), 
WHILE THE SPIRAL BANDS OF DEEP CONVECTION ARE CONTINUING TO 
CONSOLIDATE. DESPITE STRETCHED CONVECTIVE ENVELOPE, THE 091211Z F16 
SSMIS 37 GHZ MICROWAVE PASS REVEALS IMPROVING LOW-LEVEL STRUCTURE. THE 
850MB VORTICITY SIGNATURE IS ALSO CONSOLIDATING AND BECOMING MORE 
SYMMETRICAL. ENVIRONMENTAL CONDITIONS ARE MARGINALLY FAVORABLE WITH 
GOOD AMOUNTS OF MID-LEVEL MOISTURE VISIBLE IN THE 700-300 MB RELATIVE 
HUMIDITY IMAGERY, AS WELL AS WARM (27-28C) SEA SURFACE TEMPERATURES 
(SST). THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON 
THE EXTRAPOLATION FROM 091508Z METOP-C ASCAT PASS. THE INITIAL 
INTENSITY OF 40 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE 
BLEND OF AVAILABLE AGENCY AND OBJECTIVE ESTIMATES LISTED BELOW, AS 
WELL AS THE AFOREMENTIONED ASCAT PASS SHOWING MAXIMUM WINDS OF 30 KTS.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: COMPETING STEERING INFLUENCE FROM TWO
SUBTROPICAL RIDGES LOCATED TO THE SOUTHWEST AND SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 46 KTS AT 091313Z
   CIMSS ADT: 55 KTS AT 091730Z
   CIMSS AIDT: 44 KTS AT 091900Z
   CIMSS D-PRINT: 44 KTS AT 091900Z

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

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 14S IS FORECAST TO CONTINUE TRACKING
WEST-NORTHWESTWARD FOR THE NEXT 24 HOURS STEERED PRIMARILY BY THE
SUBTROPICAL RIDGE (STR) TO THE SOUTHWEST, AND TO A LESSER EXTENT,
THE STR TO THE SOUTHEAST. OVER THE FOLLOWING 24-48 HOURS THE RIDGE
TO THE SOUTHWEST WILL REORIENT TO A NORTHWEST-SOUTHEAST AXIS, WHILE
EVENTUALLY WEAKENING AND MOVING WESTWARD. AT THAT POINT TC TALIAH WILL 
BE HEADING SOUTHWESTWARD THROUGHOUT THE FORECAST PERIOD, STEERED 
PRIMARILY BY THE STRENGTHENING STR TO THE EAST-SOUTHEAST. THE STRENGTH 
OF THE RIDGE, AS WELL AS THE TIMELINE OF THE INTERACTION WILL 
DETERMINE IF THE SYSTEM WILL RECURVE OR NOT. HOWEVER, THE CURRENT 
GUIDANCE DOES NOT SUPPORT THAT SCENARIO. IN TERMS OF INTENSITY, THERE 
IS STILL SOME RAPID INTENSIFICATION SIGNAL, PRIMARILY FROM COAMPS-TC 
RI ENSEMBLE AND FRIA, HOWEVER THE PROBABILITY REMAINS LOW TO MEDIUM 
(25-45 PERCENT). AT THE SAME TIME, THE ENVIRONMENT WILL REMAIN 
FAVORABLE WITH WEAK TO MODERATE VWS, WARM SEA SURFACE TEMPERATURES 
(27-28 C) THROUGH TAU 48. THE UPPER LEVEL OUTFLOW IS ALSO FORECAST TO 
IMPROVE WITHIN THAT PERIOD, OPENING THE POTENTIAL FOR STEADY 
INTENSIFICATION. CURRENT FORECAST CALLS FOR MAXIMUM INTENSITY OF 75 
KTS BY TAU 72. PAST THE INITIAL 72 HOURS, THE ENVIRONMENT WILL QUICKLY 
DEGRADE AND COMBINE WITH THE INTRUSION OF DRY AIR, ULTIMATELY 
LEADING TO TC 14S WEAKENING THROUGH THE REMAINDER OF THE FORECAST.

MODEL DISCUSSION: DETERMINISTIC TRACK MODEL GUIDANCE IS IN OVERALL
FAIR AGREEMENT THROUGH THE INITIAL 48 HOURS, WITH ALL MODELS
PREDICTING AN UPCOMING GRADUAL TURN TOWARDS SOUTHWEST. THE
CROSS-TRACK SPREAD AT TAU 48 IS 75 NM, INCREASING TO 220 NM BY THE
END OF THE FORECAST PERIOD. MUCH HIGHER UNCERTAINTY TOWARDS THE END
OF THE TRACK IS ASSOCIATED WITH THE STRENGTH OF THE STEERING
MECHANISMS AND HOW THOSE REMAIN ASSESSED BY INDIVIDUAL MODELS. JTWC
TRACK FORECAST IS THEREFORE LAID WITH MEDIUM CONFIDENCE THROUGH TAU
72 AND LOW AFTERWARDS. JTWC FORECAST TRACK REMAINS IN CLOSE
DISTANCE OF THE MULTI-MODEL CONSENSUS. JTWC INTENSITY IS ASSESSED
WITH MEDIUM CONFIDENCE, AS ALL MODELS AGREE ON THE GENERAL TIMELINE
OF INTENSIFICATION AND WEAKENING. HOWEVER, MAXIMUM INTENSITY SPREAD
REMAINS HIGH, WITH THE POTENTIAL FOR RAPID INTENSIFICATION, AS
INDICATED BY 40-45 PERCENT FRIA PROBABILITY, REACHING AS HIGH AS 95
KTS, OFFSET BY COAMPS-TC REACHING JUST 55-60 KTS. JTWC INTENSITY
GUIDANCE IS PLACED IN CLOSE PROXIMITY TO A MULTI-MODEL CONSENSUS,
SLIGHTLY ON THE HIGHER SIDE.

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