WDXS31 PGTW 122100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 07S (DIKELEDI) WARNING 
NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.4S 43.9E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 186 NM EAST OF NACALA, MOZAMBIQUE
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS
PERSISTENT DEEP CONVECTION WITH OVERSHOOTING CLOUD TOPS OBSCURING
THE LOW LEVEL CIRCULATION CENTER AND A BAND OF FLARING CONVECTION
FORMING ALONG THE WESTERN PERIPHERY. STRONG RADIAL OUTFLOW IS
OBSERVED PRIMARILY IN THE POLEWARD DIRECTION BUT IS IMPLICATIVE OF
PRESSURE ON THE EQUATORWARD SIDE IN THE PRESENCE OF SHEAR.
EXTRAPOLATION OF A DEFINED CENTRAL EYE FEATURE ON A 121521Z RCM-3
SYNTHETIC APERTURE RADAR (SAR) NRCS IMAGE WAS USED IN CONJUNCTION
WITH ANIMATED EIR IMAGERY TO ASSESS THE INITIAL POSITION WITH HIGH
CONFIDENCE. THE INITIAL INTENSITY OF 70 KTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON A BLEND OF AGENCY SUBJECTIVE DVORAK ESTIMATES
ALONG WITH THE AFOREMENTIONED SAR DATA, WHICH WERE APPROXIMATELY 15
KTS HIGHER THAN THE RANGE OF OBJECTIVE INTENSITY ESTIMATES.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   KNES: T4.5 - 77 KTS
   DEMS: T4.0 - 65 KTS
   FMEE: T4.5 - 77 KTS
   CIMSS ADT: 55 KTS AT 121800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: THE GENERAL TRACK WILL BEGIN TO CURVE AROUND
THE STR AXIS BETWEEN TAU 24 AND 36 AND IS EXPECTED TO REMAIN
LARGELY OVER THE CHANNEL WITH MINIMAL LAND INTERACTION, ALTHOUGH
THIS REMAINS ONE OF THE PRIMARY UNCERTAINTIES IN THE FORECAST. DUE
TO THE STRONG EXHAUST CURRENTLY OBSERVED, INTENSIFICATION IS
PREDICTED AT A GRADUAL PACE AND MAY INCREASE AT A BETTER RATE WITH
AN IMPROVEMENT IN THE EQUATORWARD EXHAUST BETWEEN TAU 12-72. AFTER
ROUNDING THE STR AXIS, TRACK SPEEDS WILL ACCELERATE SOUTHEASTWARD
AND EVENTUALLY BEGIN THE TRANSITION TO AN EXTRATROPICAL CYCLONE
NEAR TAU 96. EXTRATROPICAL TRANSITION IS EXPECTED TO BE COMPLETE BY
TAU 120.

MODEL DISCUSSION: TRACK GUIDANCE IS IN FAIRLY GOOD AGREEMENT, WITH
THE EXCEPTION OF GFS-BASED AIDS TAKING THE TRACK FURTHER WEST
TOWARDS THE MOZAMBIQUE COAST. THE JTWC FORECAST CLOSELY MATCHES
THAT OF THE MULTI-MODEL CONSENSUS AND IS WEIGHTED TOWARDS THE ECMWF
GUIDANCE, WHICH IS SLIGHTLY EAST OF THE CONSENSUS. THE INTENSITY
AIDS ARE DIVERGENT ON THE EXPECTED TRENDS DUE TO TRACK
UNCERTAINTIES AND POTENTIAL FOR A BRIEF PERIOD OF LAND INTERACTION
ON THE WEST SIDE OF THE VORTEX. THEREFORE, IN LINE WITH THE JTWC
FORECAST TRACK THROUGH THE MOZAMBIQUE CHANNEL AND DUE TO RI GUIDES
NOW TRIGGERING, THE INTENSITY FORECAST IS HIGHER THAN THAT OF THE
CONSENSUS WITH LOW CONFIDENCE.

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