WDPN31 PGTW 191500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (JONGDARI) WARNING 
NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 27.7N 125.7E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 133 NM WEST-NORTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
STORM 10W (JONGDARI) WITH A WELL-DEFINED, YET COMPLETELY EXPOSED
LOW-LEVEL CIRCULATION CENTER (LLCC). 10W CONTINUES TO HAVE VERY
LITTLE ASSOCIATED CONVECTION, MOST LIKELY DUE TO THE HIGH NORTHERLY
VERTICAL WIND SHEAR IN THE AREA PREVENTING IT FROM BUILDING OVER
THE CENTER. ENVIRONMENTAL ANALYSIS INDICATES THAT 10W IS IN A
MARGINALLY UNFAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT
CHARACTERIZED BY WEAK EQUATORWARD OUTFLOW ALOFT, MODERATE TO HIGH
VERTICAL WIND SHEAR, AND WARM SEA SURFACE TEMPERATURES. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EXPOSED LLCC
SEEN IN THE ANIMATED EIR IMAGERY.  THE INITIAL INTENSITY OF 35 KTS
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE OBJECTIVE AND
SUBJECTIVE INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: THE WESTERN PERIPHERY OF A DEEP-LAYER
STR CENTERED TO THE EAST.


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T1.5 - 25 KTS
   KNES: T1.5 - 25 KTS
   CIMSS SATCON: 34 KTS AT 191200Z
   CIMSS ADT: 31 KTS AT 191200Z
   CIMSS AIDT: 34 KTS AT 191200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 20-25 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: WEAK EQUATORWARD

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: 10W IS FORECAST TO CONTINUE TRACKING
NORTHWARD, ALONG THE WESTERN PERIPHERY OF THE STR TO THE EAST
THROUGH TAU 24 AND TURN NORTH-NORTHEASTWARD THROUGH TAU 36 AS IT
BEGINS TO ROUND THE STR. THE SYSTEM IS EXPECTED TO TRACK NEAR THE 
WESTERN COAST OF SOUTH KOREA AS IT DISSIPATES. HIGH VERTICAL WIND 
SHEAR, LOW OCEAN HEAT CONTENT, AND THE LACK OF CONVECTION WILL ALL AID 
IN PREVENTING ANY FURTHER INTENSIFICATION OF THE SYSTEM. AS A RESULT,
10W WILL BEGIN WEAKENING FOR THE REMAINDER OF THE FORECAST PERIOD WITH 
DISSIPATION EXPECTED AROUND TAU 36, OFF THE WESTERN COAST OF NORTHERN 
SOUTH KOREA. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT WITH A 130 NM CROSS-TRACK SPREAD AT TAU 36. ECMWF
DETERMINISTIC NOW MAKES UP THE EASTERNMOST MEMBER, MAKING LANDFALL
SOUTH OF KUNSAN. THE GFS ENSEMBLE MEAN NOW MAKES UP THE WESTERNMOST
MEMBER, WITH A STRAIGHT NORTHWARD TRACK THROUGH TAU 36. THE JTWC
TRACK FORECAST IS PLACED CLOSE TO CONSENUS WITH MEDIUM CONFIDENCE.
INTENSITY GUIDANCE IS IN SLIGHTLY WORSE AGREEMENT, WITH MODELS
LOSING THE VORTEX AT VARYING TIMES AND REFLECTING NON-CIRCULATION
ORIENTED WINDS. HOWEVER, THE JTWC INTENSITY FORECAST STICKS CLOSE
TO CONSENSUS WITH MEDIUM CONFIDENCE.

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