WDPN31 PGTW 260900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (KULAP) WARNING NR 
003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.9N 142.5E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 85 NM SOUTHEAST OF IWO TO, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 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 THAT IS OFFSET TO THE LEFT OF THE CDO.
THIS IS READILY APPARENT IN THE 260351Z AMSR2 91GHZ MICROWAVE IMAGE
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 IMPROVED CONVECTIVE SIGNATURE. THE
AGENCY INTENSITY ESTIMATES APPEAR TO BE LAGGING BEHIND A BIT.

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: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   CIMSS SATCON: 39 KTS AT 261137Z
   CIMSS ADT: 39 KTS AT 260540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: HIGH
   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 AFTER TAU 12 
THEN ACCELERATE NORTHEASTWARD AFTER TAU 24 AS IT ROUNDS THE STR AXIS.
THE FAVORABLE CONDITIONS WILL FUEL STEADY INTENSIFICATION TO A PEAK
OF 70KTS BY TAU 48 AFTER IT GETS EXPOSED INTO STRONGER POLEWARD
OUTFLOW ASSOCIATED WITH THE PREVAILING WESTERLIES. AFTERWARD,
INCREASING VWS AND COOLING SSTS WILL BEGIN TO ERODE THE SYSTEM.
ALSO, BY TAU 48, THE CYCLONE WILL ENTER THE BAROCLINIC ZONE AND
BEGIN EXTRA-TROPICAL TRANSITION (ETT), AND BY TAU 72 WILL TRANSFORM
INTO A 55-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