WDPN31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (KAJIKI)       
WARNING NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.9N 113.6E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 325 NM EAST-NORTHEAST OF DA NANG, VIETNAM
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A CONSOLIDATING 
SYSTEM, WITH A CENTRAL DENSE OVERCAST FEATURE REBUILDING OVER AND NOW 
OBSCURING THE LOW-LEVEL CIRCULATION (LLC). EASTERLY VERTICAL WIND 
SHEAR (VWS) HAS DECREASED QUICKLY ALLOWING THE OUTFLOW TO EXPAND OVER 
THE EASTERN QUADRANT. A 230935Z GMI 89GHZ COLOR COMPOSITE MICROWAVE 
IMAGE REVEALS IMPROVED LOW-LEVEL BANDING WRAPPING INTO A WELL-DEFINED 
LOW-LEVEL CIRCULATION CENTER, WITH DEEP CONVECTIVE BANDING CONFINED 
TO THE WESTERN AND SOUTHERN SEMICIRCLES. THE INITIAL POSITION IS 
PLACED WITH MEDIUM CONFIDENCE BASED ON EXTRAPOLATION FROM THE GMI 
IMAGE. IN ADDITION TO THE IMPROVED EASTWARD OUTFLOW, UPPER-LEVEL 
OUTFLOW REMAINS ROBUST, WITH STRONG EQUATORWARD OUTFLOW AND IMPROVING 
POLEWARD OUTFLOW DRIVING THE IMPROVED CENTRAL CONVECTION. THE INITIAL 
INTENSITY OF 55 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE 
PGTW ESTIMATE, WHICH IS MORE CONSISTENT WITH THE CONVECTIVE 
STRUCTURE. CIMSS OBJECTIVE ESTIMATES RANGE FROM 40 TO 52 KNOTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
ENTRENCHED TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   CIMSS ADT: 51 KTS AT 231130Z
   CIMSS AIDT: 43 KTS AT 231130Z
   CIMSS D-MINT: 40 KTS AT 230933Z
   CIMSS D-PRINT: 52 KTS AT 231130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG WESTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: TROPICAL STORM (TS) 19W IS FORECAST TO TRACK 
WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE STR THROUGH THE FORECAST 
PERIOD, SKIRTING THE SOUTHERN COAST OF HAINAN ISLAND NEAR TAU 24. TS 
19W IS FORECAST TO INTENSIFY STEADILY TO A PEAK INTENSITY OF 75 KNOTS 
BY TAU 24 ASSUMING THE CORE OF THE SYSTEM STAYS SOUTH OF HAINAN AS 
INDICATED BY HAFS-A. AFTER TAU 24, UPWELLING COOLER WATER SHOULD 
CONTRIBUTE TO A SLIGHT WEAKENING TREND JUST PRIOR TO LANDFALL. AFTER 
TAU 48, THE SYSTEM WILL RAPIDLY WEAKEN OVERLAND AND DISSIPATE BY TAU 
72.  

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN TIGHT 
AGREEMENT THROUGH THE FORECAST PERIOD, WITH A 60-75NM CROSS-TRACK 
SPREAD FROM TAU 24 TO TAU 36. THE 230000Z ECEPS AND 230600Z GEFS 
ENSEMBLES ALSO REMAIN IN GOOD AGREEMENT LENDING HIGH CONFIDENCE TO 
THE JTWC TRACK FORECAST. RELIABLE DETERMINISTIC INTENSITY GUIDANCE 
INDICATES MODERATE POTENTIAL FOR RAPID INTENSIFICATION (RI), WITH 
PEAK INTENSITY VALUES RANGING FROM 65 TO 75 KNOTS NEAR TAU 24. 
ADDITIONALLY, RI GUIDANCE IS TRIGGERED SUGGESTING CONDUCIVE 
CONDITIONS THROUGH TAU 36.  

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: MEDIUM//
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