WDPN32 PGTW 292100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (JEBI) WARNING NR 
014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
 
SUMMARY:
   INITIAL POSITION: 25.2N 140.7E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 608 NM SOUTH OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET
 
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:

ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS

SUSTAINED DEEP, FLARING CONVECTION THROUGHOUT THE NORTHERN AND 
EASTERN PARTS OF TS 19W (JEBI), ENHANCED BY A ROBUST POLEWARD
OUTFLOW AHEAD OF AN UPPER-LEVEL TROUGH TRANSITING OVER JAPAN.
WITH THE IMPROVED VENTILATION, THE SYSTEM INTENSIFIED TO 40 KTS AND
IS CURRENTLY TRACKING NORTHWARD, STEERED BY A SUBTROPICAL RIDGE 
TO THE EAST-NORTHEAST. THE INITIAL POSITION IS PLACED WITH MEDIUM
CONFIDENCE BASED ON LOW CLOUD TRACING OF THE LOW-LEVEL CIRCULATION
THAT WAS PARTLY EXPOSED AND RECENTLY OBSCURED BY THE CENTRAL 
CONVECTION IN THE EIR LOOP. THE INITIAL INTENSITY OF 40 KTS IS 
ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE HIGH END OF AGENCY AND 
AUTOMATED DVORAK INTENSITIES, SUPPORTED BY THE 291610Z GCOMW1 
AMSR2 WINDSPEED IMAGE, AND REFLECTS THE MOSTLY SUSTAINED 6-HR 
CONVECTIVE SIGNATURE.
 
INITIAL WIND RADII BASIS: PERSISTENCE
 
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST-NORTHEAST
 
AGENCY DVORAK AND AUTOMATED FIXES: 

   PGTW: T2.0 - 30 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T1.5 - 25 KTS
   KNES: T2.0 - 30 KTS
   CIMSS SATCON: 43 KTS AT 291630Z
   CIMSS ADT: 34 KTS AT 291910Z
   CIMSS AIDT: 37 KTS AT 291910Z
 
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE

   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD
 
ANALYSIS CONFIDENCE:

   INITIAL POSITION: MEDIUM
   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 19W (JAGI) IS FORECAST TO CONTINUE TRACKING
NORTHWARD ALONG THE WESTERN PERIPHERY OF THE STEERING STR TO THE EAST-
NORTHEAST. BY TAU 12, THE CYCLONE WILL MAKE A NORTHEASTWARD TURN 
PARALLEL TO THE JAPAN ISLANDS. ENHANCED BY A MARGINALLY FAVORABLE 
ENVIRONMENT, THE PEAK INTENSITY IS FORECAST AT 60 KTS BY TAUS 36-48. 
PAST TAU 48, THE SYSTEM WILL EXPERIENCE INCREASED VERTICAL WIND SHEAR, 
AS WELL AS COOLER SEA SURFACE TEMPERATURES AND WILL BEGIN 
EXTRATROPICAL TRANSITION, WHICH IS EXPECTED TO BE COMPLETED BY THE END 
OF THE FORECAST PERIOD.
 
MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT
BOTH IN REGARDS TO TRACK AND INTENSITY, WITH THE ONLY OUTLIER BEING
NAVGEM, SUGGESTING A MORE EASTERLY INITIAL TRACK. REMAINING
CONSENSUS MEMBERS DISPLAY GOOD AGREEMENT WITH CROSS-TRACK SPREAD OF
50NM, WITH THE GALE-FORCE WIND FIELD WELL EAST OF HONSHU AND
HOKKAIDO.
 
FORECAST CONFIDENCE:

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

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