WDPN32 PGTW 302100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.1N 132.2E
   INITIAL INTENSITY: 105 KTS
   GEOGRAPHIC REFERENCE: 404 NM SOUTHEAST OF KADENA AB, OKINAWA,
JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A LARGE
SYSTEM THAT CONTINUES TO RAPIDLY INTENSIFY AND CONSOLIDATE WITH
FEEDER BANDS FROM ALL QUADRANTS WRAPPING TIGHTER INTO THE CENTRAL
DENSE OVERCAST THAT MAINTAINED A RAGGED 15-NM EYE. OUTFLOW, BOTH
POLEWARD AND EQUATORWARD ARE VIGOROUS AND PROVIDING EFFICIENT
VENTILATION TO THE ASSOCIATED CONVECTION. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE. THE INITIAL
INTENSITY OF 105KTS IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON AN
OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES (SEE
BELOW) AND REFLECTS THE IMPROVED EIR STRUCTURE. ANALYSIS INDICATES A 
HIGHLY FAVORABLE ENVIRONMENT WITH WARM SSTS IN THE PHILIPPINE SEA, 
LOW VWS, AND STRONG DUAL OUTFLOW ALOFT.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) TO
THE NORTHEAST, EAST OF JAPAN.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   RJTD: T5.0 - 90 KTS
   KNES: T6.0 - 115 KTS
   CIMSS SATCON: 106 KTS AT 301705Z
   CIMSS ADT: 112 KTS AT 301730Z
   CIMSS D-PRINT: 94 KTS AT 301800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: FORECAST PEAK INTENSITY RAISED TO
125KTS AND EXTENDED PORTION OF FORECAST CHANGED TO A
QUASI-STATIONARY STORM MOTION.  

FORECAST DISCUSSION: TY KHANUN WILL CONTINUE ON A NORTHWESTWARD
TRACK UNDER THE STEERING INFLUENCE OF THE STR TO THE NORTHEAST
TOWARD OKINAWA, PASSING APPROXIMATELY 58 NM SOUTHWEST OF KADENA AB
AROUND TAU 48 PRIOR TO DRIFTING SLOWLY INTO THE EAST CHINA SEA
(ECS). AFTER TAU 72, A SECONDARY STR, CURRENTLY ANCHORED IN THE
GULF OF POHAI, WILL COMPETE FOR STEERING AND FORCE A
QUASI-STATIONARY (QS) STORM MOTION IN THE ECS. THE HIGHLY FAVORABLE
ENVIRONMENT WILL FUEL A SECONDARY RAPID INTENSIFICATION TO A PEAK
OF 125KTS BY TAU 36. AFTERWARD, SUBSIDENCE CAUSED BY A MID-
LATITUDE TROUGH TO THE NORTH AND BEHIND THE CURRENT STR WILL STIFLE
FURTHER INTENSIFICATION. INCREASING VWS AND COOLING SST DUE TO
UPWELLING INDUCED BY THE SYSTEM QS MOTION WILL MORE RAPIDLY ERODE
THE SYSTEM DOWN TO 65 KTS BY TAU 120. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL SPREAD TO A MERE 194 NM BY TAU 72. AFTERWARD, ALL MEMBERS
INDICATE A SLOW POLEWARD RECURVATURE, ALBEIT IN A VERY WIDE SPREAD
TO 598 NM BY TAU 120. IN VIEW OF THIS, THERE IS HIGH CONFIDENCE IN
THE JTWC FORECAST TRACK UP TO TAU 72 THEN LOW CONFIDENCE AFTERWARD.


FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
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