WDPN31 PGTW 261500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (KULAP) WARNING NR 
004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 25.0N 141.8E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 30 NM EAST-NORTHEAST OF IWO TO, JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A SLOWLY
CONSOLIDATING SYSTEM WITH THE CENTRAL DENSE OVERCAST (CDO) AND THE
FEEDER BANDS PACKED ALONG THE EASTERN PERIPHERY OF A BROAD AND
RAGGED LOW LEVEL CIRCULATION (LLC) THAT IS OFFSET TO THE SOUTHWEST
QUADRANT OF THE CDO. THIS IS CORROBORATED BY A LLC FEATURE IN A
260830Z SCATTEROMETRY PASS WHERE THE INITIAL POSITION IS
EXTRAPOLATED FROM. THE INITIAL INTENSITY IS BASED ON THE AUTOMATED
DVORAK ESTIMATES THAT SEEM TO BE MORE REPRESENTATIVE OF THE 6-HR
SUSTAINED CONVECTIVE SIGNATURE. THE AGENCY INTENSITY ESTIMATES
APPEAR TO BE LAGGING BEHIND.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA.

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


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   CIMSS SATCON: 39 KTS AT 261137Z
   CIMSS ADT: 39 KTS AT 261140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   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: TS KULAP WILL TURN MORE NORTHWARD THEN BEGIN
TO ACCELERATE NORTHEASTWARD AFTER TAU 12 AS IT ROUNDS THE STR AXIS.
THE FAVORABLE CONDITIONS WILL FUEL STEADY INTENSIFICATION TO A PEAK
OF 65KTS BY TAU 48 AFTER IT GETS EXPOSED TO STRONGER POLEWARD
OUTFLOW ASSOCIATED WITH THE PREVAILING WESTERLIES. AFTERWARD,
INCREASING VWS AND COOLING SSTS WILL BEGIN TO ERODE THE SYSTEM.
ALSO, BY TAU 36, THE CYCLONE WILL ENTER THE BAROCLINIC ZONE AND
BEGIN EXTRA-TROPICAL TRANSITION (ETT), AND BY TAU 72 WILL TRANSFORM
INTO A 60-KT COLD CORE LOW WITH AN EXPANSIVE WIND FIELD.


MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY TIGHT AGREEMENT,
LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. DUE TO THE
VARIABILITY INTRODUCED BY ETT, THERE IS ONLY MEDIUM CONFIDENCE IN
THE INTENSITY FORECAST. 

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