WDPN32 PGTW 292100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR 
011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.5N 132.8E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 554 NM SOUTH-SOUTHEAST OF KADENA AB,
OKINAWA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A MEDIUM-SIZED 
SYSTEM THAT CONTINUED TO CONSOLIDATE AS THE CENTRAL DENSE OVERCAST 
(CDO) BECAME MORE ORGANIZED AND SYMMETRICAL WITH THE APPEARANCE OF A 
RAGGED FORMATIVE EYE. A DRY SLOT WRAPPING IN FROM THE NORTHWEST 
PERSISTS; HOWEVER, RAIN BANDS, ALTHOUGH FRAGMENTED, ARE TRAILING 
SOUTHWESTWARD AND FEEDING PERSISTENTLY INTO THE CDO. THE INITIAL 
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE FORMATIVE EYE 
THAT LINED UP WELL WITH A RAGGED MICROWAVE EYE IN THE 292210Z SSMIS 
IMAGE. THE INITIAL INTENSITY OF 60KTS IS PLACED WITH MEDIUM 
CONFIDENCE BASED ON THE OVERALL ASSESSMENT OF AGENCY AND THE 
AUTOMATED CIMSS D-PRINT DVORAK ESTIMATES AND REFLECTS THE 6-HR 
STRUCTURAL IMPROVEMENT. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT 
WITH LOW VWS, STRONG  COMBINED OUTFLOW, AND WARM SST TEMPERED BY THE 
DRY AIR INTRUSION.

INITIAL WIND RADII BASIS: SAR DATA.

CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE (NER) TO THE EAST
WITH N-S AXIS LINED OVER GUAM.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T3.5 - 55 KTS
   KNES: T4.5 - 77 KTS
   CIMSS D-PRINT: 58 KTS AT 291800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG EQUATORWARD
   OTHER FACTORS: MODERATE POLEWARD OUTFLOW CHANNEL INTO A TUTT
CELL TO THE NORTH.


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: TS KHANUN WILL CONTINUE ON A MORE
NORTH-NORTHWESTWARD TRACK UNDER THE STEERING INFLUENCE OF THE NER.
AFTER TAU 36, A SUBTROPICAL RIDGE (STR) TO THE NORTH WILL ASSUME
STEERING AND DRIVE THE SYSTEM ON A NORTHWESTWARD TRAJECTORY TOWARD
OKINAWA, PASSING APPROXIMATELY 66 NM SOUTHWEST OF THE KADENA AB
AROUND TAU 48 PRIOR TO DRIFTING INTO THE EAST CHINA SEA AND MAKING
LANDFALL SOUTH OF SHANGHAI AROUND TAU 90. THE FAVORABLE ENVIRONMENT
WILL FUEL A GRADUAL INTENSIFICATION AIDED BY INCREASING POLEWARD 
OUTFLOW AS THE STEERING MECHANISM SWITCHES TO THE STR TO A PEAK OF 
95KTS BY TAU 72. AFTER TAU 72, SUBSIDENCE CAUSED BY A PASSING MID-
LATITUDE TROUGH TO THE NORTH WILL WEAKEN 06W TO 65 KTS AT TAU 96. 
AFTER LANDFALL, INTERACTION WITH THE RUGGED CHINESE INTERIOR WILL 
MOSTLY BE RESPONSIBLE FOR THE RAPID EROSION, AND BY TAU 120, 06W 
WILL BE REDUCED TO 40 KTS, POSSIBLY WEAKER, AS IT TRACKS FURTHER 
INLAND.


MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL SPREAD TO A MERE 108 NM BY TAU 72 THEN TO 515 NM BY TAU
120 WITH AEMN AND GFS OFFERING A SHARP RECURVE NORTHEASTWARD AFTER
TAU 72. IN VIEW OF THIS, THERE IS HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK UP TO TAU 72 THEN MEDIUM CONFIDENCE AFTERWARD. 


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