WDPS31 PGTW 120900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05P (CODY) WARNING NR 
015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.4S 174.0E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 402 NM SOUTHWEST OF SUVA, FIJI
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND ENHANCED
INFRARED (EIR) IMAGERY DEPICT THE SYSTEM WITH DEEP BANDING
CONVECTION, WRAPPING TIGHTLY AROUND AN LLC. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED EXTRAPOLATION OF A WELL-TIMED
120530Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY OF 50KTS IS HELD
SLIGHTLY LOWER THAN THE PGTW AND HIGHER THAN ADT DVORAK ESTIMATES
AND DIRECTLY IN LINE WITH THE SATCON ESTIMATE OF 50KTS, REFLECTING
THE SUSTAINED CONVECTIVE STRUCTURE, BUT REMAINS LOWER THAN OTHER
FORECASTING AGENCIES. ANALYSIS INDICATES A MARGINAL ENVIRONMENT
WITH MODERATE TO STRONG VERTICAL WIND SHEAR, COOL SSTS, LOW-LEVEL
DRY AIR INTRUSION FROM THE WEST, AND IMPROVING POLEWARD OUTFLOW.
THE CYCLONE IS TRACKING ALONG THE WESTERN PERIPHERY OF THE STR TO
THE EAST-SOUTHEAST.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: DEEP LAYER SUBTROPICAL RIDGE (STR) TO
THE EAST-SOUTHEAST. 


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   KNES: T4.0 - 65 KTS
   PHFO: T4.0 - 65 KTS
   NFFN: T4.5 - 77 KTS
   CIMSS SATCON: 50 KTS AT 120215Z
   CIMSS ADT: 43 KTS AT 120710Z

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

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC CODY WILL CONTINUE TRACKING SOUTHEASTWARD
UNDER THE STR FOR THE REMAINDER OF THE FORECAST. AS THE SYSTEM MOVES 
MORE POLEWARD, VWS WILL CONTINUALLY INCREASE, WHILE SSTS WILL 
DECREASE. HOWEVER, POLEWARD OUTFLOW WILL ALSO INCREASE, SUSTAINING 
THE CONVECTION BETWEEN TAUS 12 AND 24. TC CODY WILL BEGIN 
TRANSITIONING INTO AN EXTRA-TROPICAL LOW BY TAU 36 AS IT ENTERS THE 
COLD BAROCLINIC ZONE. BY TAU 48 TC CODY IS EXPECTED TO COMPLETELY 
TRANSITION INTO A STRONG GALE-FORCE COLD-CORE LOW WITH AN EXPANDING 
WIND FIELD. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY TIGHT AGREEMENT WITH
THE SOLE EXCEPTION OF NAVGEM THAT DRASTICALLY SHOOTS THE VORTEX 
WESTWARD AFTER TAU 24. REGARDLESS, THERE IS HIGH CONFIDENCE IN THE 
JTWC TRACK FORECAST THAT IS LAID JUST TO THE WEST OF THE MODEL 
CONSENSUS AFTER TAU 24 TO OFFSET NAVGEM AND ONLY MEDIUM CONFIDENCE 
IN THE INTENSITY AS THE SYSTEM UNDERGOES TRANSITION INTO A COLD-CORE 
LOW. 

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