WDPN31 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 08W (DAMREY)        
WARNING NR 021//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 38.4N 144.5E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 194 NM SOUTHEAST OF MISAWA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS DEEP CONVECTIVE 
BANDING WRAPPING INTO A DEFINED LOW LEVEL CIRCULATION CENTER, WHICH 
SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. A 272034Z SSMIS 91 
GHZ MICROWAVE IMAGE SHOWS A DECAYING EYEWALL WITH DEEP CONVECTIVE 
BANDING OVER THE SOUTHERN AND EASTERN SEMICIRCLES. THE INITIAL 
INTENSITY REMAINS ASSESSED AT 60 KNOTS WITH MEDIUM CONFIDENCE BASED ON 
THE CIMSS AIDT AND SATCON ESTIMATES.  

INITIAL WIND RADII BASIS: PERSISTENCE 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   CIMSS ADT: 39 KTS AT 272340Z
   CIMSS AIDT: 65 KTS AT 280030Z
   CIMSS SATCON: 52 KTS AT 280000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG 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: TROPICAL STORM (TS) 08W IS RECURVING AROUND THE 
WESTERN PERIPHERY OF THE STR AND IS FORECAST TO BEGIN EXTRA-TROPICAL 
TRANSITION (ETT) BY TAU 12 AS IT INTERACTS WITH THE MIDLATITUDE 
WESTERLIES AND BAROCLINIC ZONE. VERTICAL WIND SHEAR WILL INCREASE TO 
HIGH LEVELS (30-35 KTS) WITH COOLING SST (25 C TO 21 C) BY TAU 36 AS 
THE SYSTEM ACCELERATES EASTWARD AND COMPLETES ETT, GAINING FRONTAL 
CHARACTERISTICS AND TRANSITIONING INTO A STORM-FORCE, COLD-CORE LOW.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE REMAINS IN TIGHT
AGREEMENT THROUGH THE FORECAST PERIOD LENDING HIGH CONFIDENCE TO
THE JTWC TRACK FORECAST. RELIABLE INTENSITY GUIDANCE SUPPORTS THE
JTWC INTENSITY FORECAST WITH MEDIUM CONFIDENCE AND SHOWS A STEADY
WEAKENING TREND AFTER TAU 12.

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