WDXS31 PGTW 142100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 04S (CHIDO) WARNING NR 
015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.2S 42.8E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 148 NM NORTHEAST OF NACALA, MOZAMBIQUE
   MOVEMENT PAST 6 HOURS: WESTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 35 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN
APPROXIMATELY 5 NM, PERIODICALLY CLOUD-FILLED EYE WITH SLIGHT
WARMING OF THE SURROUNDING CLOUD TOPS COMPARED TO THE PREVIOUS
WARNING CYCLE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON RECENT SATELLITE EYE FIXES FROM PGTW AND KNES AND A
141506Z SSMIS PASS. INITIAL INTENSITY OF 115 KTS IS ASSESSED WITH
MEDIUM CONFIDENCE ON THE UPPER END OF AVAILABLE SUBJECTIVE DVORAK
AND AUTOMATED INTENSITY ESTIMATES. THE SYSTEM HAS BECOME SLIGHTLY
LESS ORGANIZED OVER THE PAST SIX HOURS BUT REMAINS AN EXTREMELY
STRONG SYSTEM SUPPORTED BY FAVORABLE ENVIRONMENTAL CONDITIONS
INCLUDING A VERY WARM SEA SURFACE, LOW VERTICAL WIND SHEAR, AND
FAVORABLE RADIAL OUTFLOW PATTERN.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGING (STR) TO
THE SOUTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   KNES: T5.5 - 102 KTS
   CIMSS SATCON: 102 KTS AT 141620Z
   CIMSS ADT: 102 KTS AT 141500Z

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

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 04S WILL CONTINUE
TRACKING WESTWARD TO WEST-SOUTHWESTWARD UNTIL MAKING LANDFALL A FEW
HOURS PRIOR TO TAU 12. THEREAFTER, THE SYSTEM WILL TURN
INCREASINGLY POLEWARD AROUND THE NORTHWESTERN PERIPHERY OF THE
SUBTROPICAL STEERING RIDGE. TC 04S WILL LIKELY MAINTAIN INTENSITY
AT OR AROUND 115 KNOTS UNDER THE INFLUENCE OF FAVORABLE
ENVIRONMENTAL CONDITIONS INCLUDING PASSAGE OVER WARM WATER AND
SUPPORTIVE UPPER-LEVEL FLOW PRIOR TO MAKING LANDFALL. THE SYSTEM
WILL STEADILY DISSIPATE FOLLOWING LANDFALL, WITH INTENSITY DROPPING
BELOW THE WARNING THRESHOLD OF 35 KNOTS BY TAU 36.

MODEL DISCUSSION: NUMERICAL MODEL TRACK AND INTENSITY GUIDANCE ARE
IN VERY GOOD AGREEMENT THROUGHOUT THE ENTIRETY OF THE 36 HOUR
FORECAST PERIOD. THE ONLY REMAINING UNCERTAINTY LIES IN THE
NEAR-TERM INTENSITY TREND PRIOR TO LANDFALL. MODEL GUIDANCE
SUGGESTS WEAKENING OVER THE NEXT SEVERAL HOURS, PRIOR TO LANDFALL,
BUT FAVORABLE ENVIRONMENTAL CONDITIONS SUGGEST OTHERWISE. IN ANY
CASE, TC 04S WILL MAKE LANDFALL AS AN EXCEPTIONALLY INTENSE SYSTEM.

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