WDPN31 PGTW 281500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W (KULAP) WARNING NR 012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 34.7N 150.5E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 499 NM EAST OF NARITA AIRPORT
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 28 KTS
   SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) KULAP HAS LIKELY REACHED THE PEAK OF ITS TROPICAL
CYCLONE PHASE, AND IS BEGINNING THE EXTRATROPICAL TRANSITION PHASE.
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY INDICATES THE
SYSTEM DEVELOPED A BROAD AND RAGGED BANDING EYE FEATURE ABOUT SIX
HOURS AGO, BUT BY 1200Z THAT FEATURE HAS BECOME INCREASINGLY
DISORGANIZED AND RAGGED. THE MOST RECENT MICROWAVE IMAGE WAS A LOW
RESOLUTION 281058Z AMSU-B 89GHZ IMAGE WHICH SHOWED STRONG
CONVECTIVE BANDING, PARTICULARLY ON THE EASTERN SIDE OF THE SYSTEM,
WITH A LESS IMPRESSIVE BAND FURTHER OUT TO THE WEST. THE INITIAL
POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE RAGGED EYE
FEATURE IN THE EIR AND EXTRAPOLATION OF THE CENTER DEPICTED IN THE
AMSU-B IMAGE. THE INITIAL INTENSITY REMAINS SET AT 65 KNOTS WITH
MEDIUM CONFIDENCE BASED ON THE PGTW CURRENT INTENSITY ESTIMATE AND
AIDT AND OPEN-AIIR ESTIMATES OF 66 KNOTS AND 71 KNOTS RESPECTIVELY.
THEY SYSTEM CONTINUES TO ACCELERATE TO THE NORTHEAST INTO A
STEADILY DEGRADING ENVIRONMENT CHARACTERIZED BY DECREASING SSTS,
INCREASING SHEAR OFFSET BY ROBUST POLEWARD OUTFLOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: STRONG GRADIENT BETWEEN THE SUBTROPICAL
RIDGE (STR) TO THE EAST AND AN APPROACHING MID-LATITUDE TROUGH
MOVING IN FROM THE WEST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T4.5 - 77 KTS
   CIMSS ADT: 55 KTS AT 280840Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 15-20 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: SIGNIFICANT DRY AIR ENTRAINMENT ON THE SOUTH AND
EAST PORTIONS OF THE SYSTEM. 

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: BASED ON AUTOMATED AND MANUAL PHASE
CLASSIFICATION WORKSHEETS, TYPHOON KULAP HAS ALREADY BEGUN TO
TRANSITION FROM A TROPICAL CYCLONE TO A WARM CORE WARM SECLUSION
TYPE EXTRATROPICAL CYCLONE. THIS PROCESS WILL CONTINUE AS THE
SYSTEM COMES INTO PHASE WITH THE STRONG, NEGATIVELY TITLED, MAJOR
SHORTWAVE TROUGH CURRENTLY MOVING OFF THE EAST COAST OF JAPAN. COLD
AIR ADVECTION IS ALREADY INTENSIFYING TO THE NORTHWEST OF THE
SYSTEM AS EVIDENCED BY THE CUMULUS CLOUD LINES EVIDENT IN THE
SHORTWAVE INFRARED IMAGERY. WARM AIR ADVECTION IS ALSO INCREASING
TO THE NORTHEAST OF THE CENTER AND THESE PROCESSES WILL INCREASE
THE AMPLITUDE OF BOTH THE DOWNSTREAM RIDGE AND UPSTREAM TROUGH
GOING FORWARD. AS THE SYSTEM MOVES INTO THE RIGHT ENTRANCE REGION
OF A VERY STRONG 150 KNOT JET MAX BY TAU 12, THE TRANSITION PROCESS
WILL ACCELERATE. THE SYSTEM WILL CONTINUE TO INTENSIFY THROUGH
TRANSITION, CONSISTENT WITH THE SELF DEVELOPMENT PROCESS, TO A PEAK
OF 70 KNOTS AS IT BECOMES A WARM CORE SECLUSION NO LATER THAN TAU
24.   

MODEL DISCUSSION: TRACK GUIDANCE IS IN VERY GOOD AGREEMENT WITH
MINIMAL SPREAD THROUGH THE FORECAST PERIOD, LENDING HIGH CONFIDENCE
TO THE JTWC FORECAST TRACK. INTENSITY GUIDANCE IS ALSO IN GOOD
AGREEMENT, WITH ALL CONSENSUS MEMBERS SAVE COAMPS-TC INDICATING
SOME LEVEL OF NEAR-TERM INTENSIFICATION WITH PEAKS RANGING FROM
70-75 KNOTS. THE JTWC FORECAST LIES CLOSE TO THE DECAY-SHIPS AND
CONSENSUS MEAN WITH HIGH CONFIDENCE. 

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