WDPN32 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (JEBI) WARNING NR 
015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
 
SUMMARY:
   INITIAL POSITION: 25.8N 140.2E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 85 NM NORTHWEST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET
 
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A FULLY
EXPOSED, RAGGED, LOW-LEVEL CIRCULATION CENTER (LLCC) DECOUPLED
FROM THE ASSOCIATED CENTRAL CONVECTION TO THE EAST. HOWEVER, 
THE MSI LOOP ALSO SHOWS CONTINUED MODERATE POLEWARD AND WEAK
EQUATORWARD OUTFLOW. THE POLEWARD OUTFLOW CHANNEL IS BEING 
ENHANCED BY STRONG SOUTHWESTERLY WINDS AHEAD OF AN UPPER-LEVEL
TROUGH OVER JAPAN. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE EXPOSED LLCC IN THE MSI LOOP. THE INITIAL INTENSITY OF 
35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY AND 
AUTOMATED DVORAK INTENSITIES LISTED BELOW.
 
INITIAL WIND RADII BASIS: PERSISTENCE
 
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) 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: 42 KTS AT 292144Z
   CIMSS ADT: 35 KTS AT 292330Z
 
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND WEAK EQUATORWARD 
 
ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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 (JEBI) IS FORECAST TO BEGIN A 
NORTHEASTWARD TRACK AND ROUND THE AXIS OF THE STEERING STR. THE 
ENVIRONMENT REMAINS MARGINALLY FAVORABLE WITH WARM SSTS AND LOW 
VERTICAL WIND SHEAR, FUELING GRADUAL INTENSIFICATION TO A PEAK 60 KTS 
BY TAU 36. AFTERWARD, IT WILL BEGIN EXTRATROPICAL TRANSITION (ETT) 
WHICH IS EXPECTED TO CONCLUDE AT THE END OF THE FORECAST PERIOD - BY 
TAU 48.
 
MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN FAIR
AGREEMENT IN REGARD TO THE TRACK GUIDANCE WITH CROSS-TRACK SPREAD
OF 42 NM BY TAU 24, WITH THE ONLY OUTLIER STILL BEING NAVGEM,
SUGGESTING A MORE EASTERLY INITIAL TRACK. JTWC TRACK IS LAID IN
CLOSE PROXIMITY TO THE MULTI-MODEL CONSENSUS AND IS TAKING JEBI
SLIGHTLY CLOSER TO HONSHU THAN WITH THE PREVIOUS RUN, HOWEVER THE
GALE-FORCE WINDS WILL PRIMARILY REMAIN CONTAINED WITHIN THE EASTERN
SEMICIRCLE OF THE SYSTEM. INTENSITY GUIDANCE ALSO REMAINS IN GOOD
AGREEMENT AMONG THE CONSENSUS MEMBERS, PRIMARILY INDICATING SLOW
AND STEADY INTENSIFICATION, WITH THE PEAK AT TAU 36, WHEN THE
SYSTEM BEGINS ETT. THE ONLY OUTLIER IN THE GUIDANCE IS GFS-DRIVEN
COAMPS-TC, WHICH PREDICTS RAPID INTENSIFICATION OUT TO 95 KTS BY
TAU 36.
 
FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM//
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