WDPN31 PGTW 140900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (BEBINCA)       
WARNING NR 018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 27.4N 130.3E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 144 NM EAST-NORTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 15 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS LOPSIDED RADIAL 
OUTFLOW, WITH THE BETTER OUTFLOW FAVORING THE EQUATORWARD SIDE. A 
POCKET OF DRY AIR IS EVIDENT ON THE NORTH SIDE OF THE SYSTEM, WHICH IS 
LINGERING EVIDENCE OF A TUTT CELL TO THE NORTH WHICH HAS BEEN HINDERING 
TS BEBINCA'S DEVELOPMENT DUE TO CONVERGENCE ALOFT AND SUBSIDENT AIR. A 
SECONDARY TUTT CELL ALSO EXISTS TO THE WEST OF THE SYSTEM, WHICH IS 
PRODUCING A SUBSTANTIAL AMOUNT OF DRY AIR TO THE WEST. ANIMATED RADAR 
SCANS SHOW RADIAL CONVECTIVE BANDS WITH ISOLATED THUNDERSTORMS WITHIN 
THE BANDS AND A MORE INTENSE AREA OF CONVECTION WRAPPED AROUND THE 
EASTERN INNERMOST BAND. A 140446Z AMSR2 IMAGE DEPICTS A RAGGED 
MICROWAVE EYE AND WAS USED ALONG WITH ANIMATED RADAR DATA TO DETERMINE 
THE CURRENT POSITION WITH HIGH CONFIDENCE. THE CURRENT INTENSITY COULD
ONLY BE ASSESSED WITH MEDIUM CONFIDENCE AND WAS DETERMINED BASED ON
THE STRUCTURE OF THE SYSTEM, OBJECTIVE INTENSITY AID TRENDS, AND
AGENCY SUBJECTIVE DVORAK ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: OTHER 

CURRENT STEERING MECHANISM: AN EAST-WEST ORIENTED EXTENSION OF A
SUBTROPICAL RIDGE TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T3.5 - 55 KTS
   KNES: T3.5 - 55 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 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: THE SYSTEM HAS BEEN DRIVEN NORTHWESTWARD UNDER
THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE TO THE EAST, BUT IT
WILL SOON TURN TO A MORE WESTWARD TRACK AS A RESULT OF AN EAST-WEST
ORIENTED EXTENSION OF THE SUBTROPICAL RIDGE, WHICH IS ACTING AS A
STRONG BARRIER TO THE NORTH OF THE SYSTEM. THE SYSTEM WILL MAINTAIN
A FASTER PACE THAN THE CLIMATOLOGICAL AVERAGE AS IT CROSSES THE
RYUKYU ISLAND CHAIN IN THE NEXT SIX HOURS. THE ENVIRONMENT WILL BE
FAVORABLE FOR DEVELOPMENT, BUT THERE WILL BE LIMITED OPPORTUNITY
FOR TS 14W TO INTENSIFY MUCH FURTHER BEFORE IT ARRIVES AT THE ASIAN
CONTINENT NEAR TAU 48. ONCE THE SYSTEM MAKES LANDFALL IN CHINA, IT
WILL QUICKLY DISSIPATE OVER LAND BY TAU 72.

MODEL DISCUSSION: THE MODEL GUIDANCE HAS BEEN IN GOOD AGREEMENT
CONCERNING THE WESTWARD TRACK INTO CHINA, WHICH CLOSELY MIRRORS THE
JTWC FORECAST. THERE IS A CROSS TRACK SPREAD OF 55 NM IN THE
RELIABLE MODEL GUIDANCE AT TAU 48. THERE IS SLIGHTLY MORE
UNCERTAINTY TOWARDS TAU 72, WHICH SHOWS THE ECMWF TURNING THE
SYSTEM SOUTHWESTWARD AND THE GFS FAVORING A NORTH-NORTHWESTWARD
TRACK. THE JTWC FORECAST IS WEIGHTED MORE HEAVILY ON THE ECMWF SIDE
OF THE TRACK CONSENSUS. THE INTENSITY GUIDANCE SHOWS LESS AGREEMENT AND 
A WIDER SPREAD OF INTENSITIES, WITH A 40-45 KT SPREAD AT TAU 24 AND TAU 
36. CONSIDERING THE EFFECTS OF THE DRY AIR AND LAND INTERACTION, THE 
JTWC FORECAST IS ON THE CONSERVATIVE SIDE OF THE INTENSITY GUIDANCE.

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