WDPN32 PGTW 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 19W (JEBI) WARNING 
NR 010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.1N 141.9E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 165 NM SOUTH-SOUTHEAST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN
ASYMMETRICALLY STRUCTURED TD 19W, WITH MAJORITY OF THE DEEP
CONVECTION FLARING INSIDE THE EASTERN SEMICIRCLE OF THE BROAD
CIRCULATION. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE
BASED ON A NEARLY FULLY EXPOSED LLCC LOCATED TO THE WEST OF THE
DEEP CONVECTION. A TUTT CELL PREVIOUSLY LOCATED TO THE NORTH IS 
LOCATED TO THE WEST OF THE SYSTEM IS CURRENTLY INHIBITING ANY 
CONVECTIVE DEVELOPMENT OVER THIS SIDE OF THE DEPRESSION. AT THE SAME 
TIME MODERATE EASTWARD OUTFLOW DUE TO UPPER LEVEL DIFFLUENCE IS AIDING 
IN THE SUSTAINMENT AND DEVELOPMENT OF THE CONVECTION OVER THE EASTERN 
PORTION OF THE SYSTEM. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED 
WITH HIGH CONFIDENCE BASED ON AGENCY DVORAK AND AUTOMATED FIXES LISTED 
BELOW. 

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND 
RADII).

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST OF
THE SYSTEM

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.0 - 30 KTS
   CIMSS SATCON: 39 KTS AT 281529Z
   CIMSS ADT: 41 KTS AT 281730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE EASTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TD 19W IS FORECAST TO TRACK NORTHWESTWARD
ALONG THE PERIPHERY OF THE STR TO THE NORTHEAST UNTIL TAU 24, BY
WHICH TIME IT WILL START TURNING POLEWARD, EVENTUALLY RECURVING
TOWARDS THE NORTHEAST. THE SYSTEM IS CURRENTLY UNDER A MIXED SET OF
ENVIRONMENTAL CONDITIONS, INCLUDING ELEVATED VERTICAL WIND SHEAR
AND UPPER-LEVEL CONVERGENCE AND SUBSIDENCE OVER THE WESTERN
SEMICIRCLE INHIBITING DEVELOPMENT, OFFSET HOWEVER BY HIGH SSTS AND
OCEAN HEAT CONTENT. AS THE UPPER-LEVEL LOW WEAKENS, TD 19W IS
EXPECTED TO STEADILY DEVELOP AND REACH PEAK INTENSITY OF JUST UNDER
TYPHOON STRENGTH BY TAU 48. AT THAT TIME, TD 19W WILL ALSO BEGIN
EXTRATROPICAL TRANSITION, AS IT ENCOUNTERS MIDLATITUDE WESTERLY
WINDS, AND IS EXPECTED TO BECOME FULLY EXTRATROPICAL BY THE END OF
THE FORECAST PERIOD.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT
THROUGHOUT THE FORECAST PERIOD IN REGARDS TO THE TRACK, WITH 90 NM
CROSS-TRACK SPREAD BY TAU 72. INTENSITY GUIDANCE IS IN FAIR
AGREEMENT, WITH MAJORITY OF THE ESTIMATES SHOWING A DECREASE IN
MAXIMUM INTENSITY AS COMPARED TO PREVIOUS RUNS, CURRENTLY TAKING
THE SYSTEM OUT TO PEAK INTENSITY OF 60 KTS. WHILE THE RAPID
INTENSIFICATION PROBABILITY IS LOWER THAN 30 PERCENT, JTWC FORECAST
IS PLACED SLIGHTLY ABOVE THE MULTIMODEL CONSENSUS ACCOUNTING FOR A
BRIEF PERIOD OF FAVORABLE ENVIRONMENTAL CONDITIONS BETWEEN TAU 12
AND 48.

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