WDPN31 PGTW 110300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (MARIA) WARNING NR 
017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 37.5N 144.7E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 239 NM SOUTHEAST OF MISAWA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS CONVECTIVE
BANDING WRAPPING INTO AN OBSCURED LOW-LEVEL CIRCULATION CENTER
(LLCC) COVERED BY DEEP CONVECTION. WATER VAPOR IMAGERY DEPICTS DRY
AIR WRAPPING INTO THE CENTER OF THE CIRCULATION FROM THE SOUTH AND
SOUTHWEST WHILE MOIST OUTFLOW FLOWS STRONGLY POLEWARD. A 102128Z
GPM GMI 89GHZ MICROWAVE IMAGE DEPICTS THE COLLAPSING UPPER-LEVEL
STRUCTURE WITH PERSISTENT CENTRALIZED DEEP CONVECTION. THE
WEAKENING NATURE OF TROPICAL STORM (TS) 06W CAN BE ATTRIBUTED TO
THE UNFAVORABLE UPPER-LEVEL ENVIRONMENT DUE TO PROXIMITY TO AN
UPPER-LEVEL JET ABOVE HOKKAIDO ISLAND, JAPAN AND DRY AIR
ENTRAINMENT DESPITE FAVORABLE ELEMENTS OF LOW VERTICAL WIND SHEAR
AND WARM SEA SURFACE TEMPERATURES (SST). THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON ANIMATED MSI. THE INITIAL
INTENSITY OF 45 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE
AGENCY AND OBJECTIVE FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE AND OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: A SUBTROPICAL RIDGE (STR) SPANNING FROM
THE EAST TO NORTHEAST OF TS 06W.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T2.0 - 30 KTS
   KNES: T2.5 - 35 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 5-10 KTS
   SST: 27-28 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 06 WILL CONTINUE TO TRACK NORTHWEST
ULTIMATELY ACROSS THE MAINLAND OF JAPAN UNDER THE STEERING
INFLUENCE OF THE STR TO THE EAST. THE SYSTEM WILL CONTINUE TO
WEAKEN OVER THE NEXT 48 HOURS AS THE UPPER-LEVEL ENVIRONMENT
BECOMES UNFAVORABLE, BUT ALSO DUE TO COOL SST THAT WILL BE DRAWN
DOWN THE EASTERN COAST OF JAPAN AND CUT OFF THE HEAT ENGINE OF THE
STORM. UPON MAKING LANDFALL PRIOR TO TAU 24, TS 06W WILL CONTINUE
TO WEAKEN AS IT INTERACTS WITH THE MOUNTAINOUS TOPOGRAPHY OF
NORTHERN JAPAN. THE SYSTEM WILL CONTINUE TO WEAKEN AFTER COMING
BACK OUT OVER WATER PRIOR TO TAU 36, AT WHICH TIME THE SYSTEM WILL
CONTINUE TO DISSIPATE THROUGH THE END OF THE FORECAST WHILE
REMAINING IN AN OVERALL UNFAVORABLE ENVIRONMENT FOR
INTENSIFICATION. IT IS ALSO POSSIBLE THAT THE LAND INTERACTION MAY
LEAVE TS 06W UNIDENTIFIABLE AND UNTRACKABLE AFTER MAKING ITS WAY
ACROSS NORTHERN JAPAN.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE STRONGLY AGREES ON
TS 06W TRACKING NORTHWESTWARD WHILE STEERED BY THE STR TO THE EAST.
THE HIGH CONFIDENCE LEVEL IN THE FORECAST TRACK IS REFLECTED IN THE
TIGHT CROSS-TRACK SPREAD OF 60NM BY THE END OF THE FORECAST PERIOD.
THE JTWC INTENSITY GUIDANCE ALSO CONFIRMS THE HIGH CONFIDENCE IN
THE INTENSITY FORECAST, FORECASTING CONSISTENTLY WEAKENING
INTENSITY. THE ONLY MEMBER OF THE JTWC INTENSITY CONSENSUS IS HWRF,
WHICH FORECASTS THAT THE SYSTEM WILL WEAKEN MORE GRADUALLY AND BE A
MERE 5KTS ABOVE THE OTHER MEMBERS INTERPRETATIONS (35KTS FOR OTHER
MEMBERS) AT TAU 24.

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