WDPS31 PGTW 122100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05P (CODY) WARNING NR 
017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.9S 175.2E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 445 NM SOUTH-SOUTHWEST OF SUVA, FIJI
   MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD,
PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION (LLC) WITH DECAYING DEEP
CONVECTION SHEARED TO THE SOUTH. A 121646Z SSMIS 91GHZ COLOR
COMPOSITE MICROWAVE IMAGE INDICATES TIGHTLY-WRAPPED LOW-LEVEL
BANDING WRAPPING INTO A DEFINED, ELONGATED CENTER WITH DEEP
CONVECTIVE BANDING OVER THE SOUTHERN SEMICIRCLE. THE INITIAL
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE SSMIS IMAGE.
THE INITIAL INTENSITY OF 50 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON AN AVERAGE OF THE PGTW AND KNES DVORAK CURRENT INTENSITY
ESTIMATES, AND IS ALSO SUPPORTED BY THE MOST RECENT CIMSS SATCON
ESTIMATE. TC 05P IS LOCATED UNDER STRONG WESTERLY FLOW ALOFT WITH
MODERATE TO STRONG VERTICAL WIND SHEAR OFFSET BY ROBUST POLEWARD
OUTFLOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO
THE EAST AND NORTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   KNES: T3.0 - 45 KTS
   CIMSS SATCON: 48 KTS AT 121328Z
   CIMSS ADT: 37 KTS AT 121740Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 20-30 KTS
   SST: 25-26 CELSIUS
   OUTFLOW: MODERATE POLEWARD

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: TC 05P IS EXPECTED TO TRACK SOUTH-SOUTHEASTWARD 
THROUGH THE FORECAST PERIOD ALONG THE SOUTHWESTERN PERIPHERY OF THE 
DEEP-LAYERED STR. HOWEVER, THE SYSTEM IS EXPECTED TO SLOW SLIGHTLY 
AS A STRONG HIGH BUILDS TO THE SOUTH AND SLOWS ITS POLEWARD 
PROGRESS. THE SYSTEM WILL MAINTAIN AN INTENSITY OF 45-50 KNOTS 
THROUGH THE FORECAST PERIOD. TC CODY WILL TRACK OVER COOLER SST (24-
25C) AND INTERACT WITH A STRONG BAROCLINIC ZONE ASSOCIATED WITH A 
SUBTROPICAL JET TO THE SOUTH. THE SYSTEM WILL LIKELY GAIN FRONTAL 
CHARACTERISTICS BY TAU 36 ALTHOUGH THE SYNOPTIC PATTERN IS NOT THE 
CLASSIC RE-CURVE SCENARIO. AFTER TAU 36, THE SYSTEM WILL REMAIN A 
STRONG GALE-FORCE LOW AS IT TRACKS TOWARD AND OVER NORTH ISLAND, NEW 
ZEALAND AND SHOULD MAINTAIN DEEP CONVECTION OVER THE SOUTHERN 
SEMICIRCLE WITH SUPPORT FROM AN APPROACHING MAJOR SHORTWAVE TROUGH. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS TIGHTLY
CLUSTERED WITH A 30NM SPREAD IN SOLUTIONS AT TAU 36 LENDING HIGH
CONFIDENCE TO THE JTWC FORECAST TRACK. ADDITIONALLY, ENSEMBLE
GUIDANCE (EPS AND GEFS) REMAINS IN TIGHT AGREEMENT ALTHOUGH THERE
IS INCREASING UNCERTAINTY IN THE TRACK NEAR NEW ZEALAND. 

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