WDPN31 PGTW 260900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 08W (DAMREY) WARNING NR 
014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 26.1N 152.9E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 633 NM EAST OF IWO TO, JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 21 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS AN ELONGATED
BUT CONSOLIDATING SYSTEM WITH A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION THAT HAS MOSTLY MAINTAINED ITS OVERALL CONVECTIVE
STRUCTURE AS IT ACCELERATES POLEWARD. THE INITIAL POSITION
IS PLACED WITH HIGH CONFIDENCE BASED ON THE MSI LOOP. THE INITIAL
INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE HIGH END
OF AGENCY AND AUTOMATED DVORAK ESTIMATES TO REFLECT THE SUSTAINED
CONVECTIVE STRUCTURE. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT
WITH WARM SST, LOW VWS, AND STRONG VENTILATION ALOFT.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T2.5 - 35 KTS
   KNES: T3.0 - 45 KTS
   CIMSS ADT: 45 KTS AT 260700Z

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: TS DAMREY WILL CONTINUE TO TRACK
NORTH-NORTHWESTWARD UNDER THE STR. AFTER TAU 24, A MID-LATITUDE
TROUGH TRANSITING FROM THE NORTHWEST WILL WEAKEN THE STR AND ALLOW
THE SYSTEM TO TRACK MORE NORTHWARD THEN ACCELERATE NORTHEASTWARD
AFTER TAU 36. THE FAVORABLE ENVIRONMENT WILL FUEL A MODEST
INTENSIFICATION TO A PEAK OF 65KTS BY TAU 36 AS IT CRESTS THE STR 
AXIS. AFTERWARD, INCREASING VWS AND COOLING SST WILL BEGIN TO
ERODE THE SYSTEM. CONCURRENTLY BY TAU 48, TS 08W WILL ENTER THE
BAROCLINIC ZONE AND BEGIN EXTRA-TROPICAL TRANSITION AND, BY TAU 72,
WILL TRANSFORM INTO A COLD-CORE LOW WITH EXPANDING GALE-FORCE
WINDS. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH
GRADUAL AND EVEN SPREAD TO 222NM BY TAU 72, LENDING HIGH CONFIDENCE
TO THE JTWC TRACK FORECAST.

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