WDPN31 PGTW 280900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (MAWAR) 
WARNING NR 034//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
  INITIAL POSITION: 17.5N 127.9E
  INITIAL INTENSITY: 105 KTS
  GEOGRAPHIC REFERENCE:  540 NM SOUTH OF KADENA AB, OKINAWA
  MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KNOTS
  SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 02W HAS STEADILY WEAKENED OVER THE PAST DAY FROM
135 KNOTS AT 270600Z TO THE CURRENT INTENSITY OF 105 KNOTS.
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS
DEEP CONVECTIVE BANDING WRAPPING AROUND A RAGGED 9NM EYE WHILE
CYCLING QUICKLY. OVERALL, THE CONVECTIVE STRUCTURE HAS
WEAKENED AND BECOME MORE FRAGMENTED OVER THE NORTHERN SEMICIRCLE
WHILE MAINTAINING OVER THE CORE. ENVIRONMENTAL CONDITIONS HAVE
DEGRADED SLOWLY WITH COOLING SST VALUES (28C) AND DECREASED
POLEWARD OUTFLOW (ESPECIALLY OVER THE NORTHWESTERN PERIPHERY)
BUT REMAIN MARGINALLY FAVORABLE. ALTHOUGH THERE IS CONVERGENT
FLOW AND SUBSIDENCE ALONG THE NORTHWESTERN AND NORTHERN
PERIPHERIES OF THE SYSTEM, THERE IS NO EVIDENCE OF SIGNIFICANT
DRY AIR ENTRAINMENT. SST VALUES ARE MODERATELY FAVORABLE UNDER
THE CORE AND SOUTHERN SEMICIRCLE BUT ARE COOLER AND UNFAVORABLE
(26-27C) UNDER THE NORTHERN SEMICIRCLE. ADDITIONALLY, COOL
UPWELLING WATER IS LIKELY (AND DEPICTED IN HWRF) DUE TO THE
SHALLOW WARM LAYER, WHICH ALSO MAY BE CONTRIBUTING TO THE STEADY
WEAKENING TREND. A 280504Z AMSR2 89GHZ MICROWAVE IMAGE REVEALS
A NEAR-COMPLETE EYEWALL (BREAK OVER THE SSE) SURROUNDING A
WELL-DEFINED MICROWAVE EYE FEATURE WITH INTENSE SPIRAL BANDING
OVER THE SOUTHERN SEMICIRCLE AND BROADER, MORE FRAGMENTED
CONVECTIVE BANDING ELSEWHERE. THERE IS HIGH CONFIDENCE IN THE
INITIAL POSITION BASED ON THE EIR AND AMSR2 IMAGERY. THE INITIAL
INTENSITY IS ASSESSED AT 105 KNOTS BASED ON THE AGENCY CURRENT
INTENSITY ESTIMATES OF 102 KNOTS AS WELL AS THE LATEST ADT AND
AIDT (104 KNOTS) ESTIMATES.  

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR)
POSITIONED TO THE NORTH AND NORTHEAST 

AGENCY DVORAK AND AUTOMATED FIXES: 
  PGTW: T5.5 - 102 KTS
  RJTD: T5.5 - 102 KTS
  KNES: T5.5 - 102 KTS
  CIMSS ADT: 110 KTS AT 280600Z 

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
  VWS: 5-10 KTS
  SST: 28 CELSIUS
  OUTFLOW: MODERATE RADIAL 

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: TY 02W IS FORECAST TO TRACK WEST-NORTHWESTWARD
TO NORTHWESTWARD OVER THE NEXT TWO DAYS BUT WILL GRADUALLY SLOW
SIGNIFICANTLY BY DAY 3 AS IT ENTERS A COMPETING STEERING
ENVIRONMENT BETWEEN A STR TO THE EAST AND A STR TO THE WEST OVER
SOUTHEAST CHINA. STEADY WEAKENING IS ANTICIPATED DUE TO COOLING
SST (26-27C) VALUES AND UPWELLING COOLER WATER AS THE SYSTEM SLOWS.
AFTER DAY 3, TY 02W WILL DRIFT POLEWARD WITHIN THE COMPETING STEERING
PATTERN WHILE WEAKENING STEADILY DUE TO COOLER SST VALUES AND DRY AIR
ENTRAINMENT. 

MODEL DISCUSSION: DETERMINISTIC GUIDANCE REMAINS IN TIGHT AGREEMENT
THROUGH TAU 48 THEN DIVERGES WITH INCREASING UNCERTAINTY THROUGH
THE REMAINDER OF THE FORECAST PERIOD. IN GENERAL, THE 500MB FLOW
REMAINS ZONAL OVER THE EAST CHINA SEA AND JAPAN WITH A STRONG JET
OVER KOREA AND JAPAN BUT NO DEEP, DYNAMIC SHORTWAVE TROUGHS EVIDENT
TO RAPIDLY RECURVE THE SYSTEM POLEWARD. THIS LACKLUSTER PATTERN IS
REFLECTED IN THE ECMWF AND GFS (EPS AND GEFS) PROBABILISTIC GUIDANCE,
WHICH SHOW A WIDE EAST-WEST SPREAD OF SOLUTIONS WITH SLOW TRACK
SPEEDS.      

FORECAST CONFIDENCE:
  TRACK 0 - 72 HR: HIGH
  TRACK 72-120 HR: MEDIUM
  INTENSITY 0 - 72 HR: MEDIUM
  INTENSITY 72-120 HR: MEDIUM//

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