WDXS32 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (FOURTEEN) WARNING 
NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.1S 74.5E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 436 NM SOUTH-SOUTHEAST OF DIEGO GARCIA
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A CONSOLIDATING 
MEDIUM-SIZED SYSTEM WITH FLARING CENTRAL CONVECTION AND FORMATIVE 
RAIN BANDS FEEDING IN FROM THE SOUTHERN PERIPHERY. THE INITIAL 
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON A RAGGED BUT 
DEFINED LOW LEVEL CIRCULATION FEATURE IN THE 220416Z AMSU-B MICROWAVE 
IMAGE. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED 
ON FOUR CLOSELY-CLUSTERED AND EQUAL AGENCY DVORAK ESTIMATE FIXES. TC 
14S IS IN A FAVORABLE ENVIRONMENT WITH LOW VWS, MODERATE POLEWARD 
OUTFLOW, AND WARM SST.

INITIAL WIND RADII BASIS: SMAP DATA.

CURRENT STEERING MECHANISM: LOW- TO MID-LAYER SUBTROPICAL RIDGE
(STR) TO THE SOUTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   DEMS: T2.5 - 35 KTS
   FMEE: T2.5 - 35 KTS

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

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: TC 14S WILL CONTINUE ON A GENERALLY 
SOUTHWESTWARD TRACK UNDER THE STR. THE FAVORABLE ENVIRONMENT WILL 
FUEL INTENSIFICATION TO A PEAK OF 55KTS AT TAUS 36-48. AFTERWARD, 
EQUILIBRIUM IN THE ENVIRONMENTAL DYNAMICS WILL SUSTAIN AN INTENSITY
AROUND 50KTS FOR THE REMAINDER OF THE FORECAST.  

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH A
GRADUAL AND EVEN SPREAD TO 187NM BY TAU 120. HOWEVER, GIVEN THE
FORMATIVE NATURE OF THE CYCLONE, THERE IS ONLY MEDIUM CONFIDENCE IN
THE JTWC TRACK AND INTENSITY FORECASTS. 

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