WDPN31 PGTW 261500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (CHAMPI) WARNING NR 
023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 27.0N 140.3E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 499 NM SOUTH OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 21 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THE
SYSTEM CONTINUES TO WEAKEN, ELONGATE, AND UNRAVEL AS IT ENTERS A HIGH
VWS AREA UNDER THE STRONG WESTERLIES. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON A RAGGED LOW LEVEL CIRCULATION
FEATURE IN THE 260909Z SSMIS 91H MICROWAVE IMAGE. THE INITIAL
INTENSITY OF 55 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON AN
OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK FIXES AND
REFLECTS THE WEAKENING STATE.

INITIAL WIND RADII BASIS: PERSISTENCE. WIND RADII PROPORTIONALLY
REDUCED FROM PREVIOUS WARNING SANS SCATTEROMETRY DATA. 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF THE STR TO THE
EAST-SOUTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T3.5 - 55 KTS
   CIMSS ADT: 47 KTS AT 261120Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 25-30 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS CHAMPI WILL ACCELERATE NORTHEASTWARD ON THE
POLEWARD SIDE OF THE STEERING STR AND BY TAU 36 WILL BE 380NM EAST
OF MISAWA AB, JAPAN. THE SYSTEM WILL GRADUALLY WEAKEN UNDER THE 
HIGHLY UNFAVORABLE ENVIRONMENT. CONCURENTLY, BY TAU 24, TS 06W WILL 
BEGIN TO INTERACT WITH THE BAIU BOUNDARY AND START EXTRA-TROPICAL 
TRANSITION AND BY TAU 36, WILL TRANSFORM INTO A GALE-FORCE COLD CORE 
LOW WITH AN EXPANSIVE WIND FIELD AS IT GETS EMBEDDED IN THE 
BAROCLINIC ZONE.

MODEL DISCUSSION: NUMERIC MODELS REMAIN TIGHT AND GRADUALLY AND
EVENLY SPREAD TO A MERE 110NM AT TAU 120, LENDING HIGH CONFIDENCE
IN THE JTWC TRACK FORECAST. THE JTWC INTENSITY FORECAST IS ALSO IN
GOOD AGREEMENT WITH MODEL SOLUTIONS WHICH SHOW A STEADY WEAKENING
TREND. 

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