WDPN31 PGTW 161500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (LAN) WARNING NR 
036//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 40.9N 136.5E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 216 NM WEST OF MISAWA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 15 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A FULLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH MINIMAL FLARING
CONVECTION BEING RAPIDLY EVACUATED POLEWARD. A 160859Z SSMIS 91GHZ
MICROWAVE IMAGE REVEALS A BROAD AND DEFORMED FULLY EXPOSED LLCC
WITH MINIMAL CONVECTIVE COVER. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON EIR AND SSMIS IMAGERY. THE INITIAL
INTENSITY OF 35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON
AGENCY DVORAK INTENSITY ESTIMATES AND CIMSS DPRINT INDICATING 35
KTS WHILE CIMSS ADT IS SHOWING A LOWER ESTIMATE OF 29KTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T2.5 - 35 KTS
   CIMSS ADT: 29 KTS AT 161140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 25-30 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: STRONG 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: TS 07W IS FORECAST TO MAINTAIN ITS GRADUAL
POLEWARD CURVE TOWARD THE SEA OF OKHOTSK THROUGHOUT THE FORECAST
PERIOD. OVER THE NEXT 12 HOURS, STRONG POLEWARD OUTFLOW ALOFT WILL
LARGELY NEGATE STEADILY MOUNTING VERTICAL WIND SHEAR (VWS),
RESULTING IN A VERY SLOW DECLINE OF INTENSITY DURING THAT TIME.
SHORTLY AFTER TAU 12, VWS TOGETHER WITH COOL DRY AIR ENTRAINING THE
SYSTEM WILL BEGIN TO DRIVE INTENSITY VALUES DOWN. AT THE SAME TIME,
THE SYSTEM WILL BEING TO INTERACT WITH A WEAK BAROCLINIC ZONE AS IT
PROCEEDS POLEWARD OF THE 44TH PARALLEL, THIS WILL INITIATE
EXTRA-TROPICAL TRANSITION (ETT). AS THE SYSTEM CONTINUES TO WEAKEN
AND INTEGRATE INTO THE MID-LATITUDE TROUGH, IT WILL CONTINUE
THROUGH ETT UNTIL ENTERING THE SEA OF OKHOTSK WHERE IT WILL
COMPLETE ETT NEAR TAU 36.

MODEL DISCUSSION: NUMERICAL MODELS AND RELIABLE MODEL INTENSITY
GUIDANCE ARE BOTH IN GOOD AGREEMENT AND DEVIATE VERY LITTLE FROM
THE MULTI-MODEL CONSENSUS. THE JTWC TRACK AND INTENSITY FORECASTS
ARE THEREFOR PLACED CLOSE TO THEIR RESPECTIVE CONSENSUS MODELS WITH
OVERALL HIGH CONFIDENCE.

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