WDPN31 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 03W (GUCHOL) WARNING NR 010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.2N 131.2E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 646 NM SOUTH-SOUTHEAST OF KADENA AB, OKINAWA
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP
CONVECTION CONSOLIDATING AROUND A RAGGED, CLOUD-FILLED EYE WITH
EXTENSIVE SPIRAL BANDING. A 080654Z SSMIS 91GHZ MICROWAVE IMAGE
DEPICTS AN OBLONG EYEWALL WITH A BREAK OVER THE NORTH QUADRANT,
WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE.
ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE WITH RADIAL OUTFLOW AND
LOW VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES REMAIN CONDUCIVE
AT 28 TO 29C. THE INITIAL INTENSITY OF 70 KTS IS ASSESSED WITH HIGH
CONFIDENCE BASED ON THE PGTW AND RJTD DVORAK ESTIMATES, AND A
080444Z AMSR2 WINDSPEED IMAGE MAXIMUM WIND SPEED VALUE OF 73 KNOTS. 
ADT AND AIDT ESTIMATES REMAIN TOO LOW, HOWEVER, THE 080700Z DPRINT 
OBJECTIVE ESTIMATE OF 79 KNOTS AND 080653Z DMINT OBJECTIVE ESTIMATE 
OF 75 KNOTS GENERALLY SUPPORT THE INITIAL INTENSITY ESTIMATE. THE 
INITIAL WIND RADII ARE BASED ON A DETAILED ANALYSIS OF THE 080444Z 
AMSR2 WINDSPEED IMAGE.

INITIAL WIND RADII BASIS: AMSR2 WINDSPEED IMAGE

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) POSITIONED TO
THE EAST (WEAK) AND NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T4.0 - 65 KTS
   KNES: T5.0 - 90 KTS
   CIMSS SATCON: 60 KTS AT 080500Z
   CIMSS ADT: 55 KTS AT 080530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE RADIAL

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: TY 03W IS FORECAST TO RECURVE POLEWARD AROUND
THE WESTERN PERIPHERY OF THE STR OVER THE NEXT 48 HOURS WITH A PEAK
INTENSITY OF 90 KNOTS FROM TAU 24 TO TAU 36. AFTER TAU 48, THE
SYSTEM WILL TRACK ALONG THE NORTHWEST PERIPHERY OF THE STR WITHIN
THE SUBTROPICAL WESTERLIES, WHICH WILL EVENTUALLY LEAD TO
SUBTROPICAL TRANSITION (STT). THE FRONTAL ZONE IS EXPECTED TO
REMAIN WELL TO THE NORTH, THEREFORE, EXTRA-TROPICAL TRANSITION IS
UNLIKELY SOUTH OF HONSHU. AS TY 03W TRACKS MORE POLEWARD, IT WILL
INTERACT WITH THE SUBTROPICAL JET AND COMPLETE STT JUST AFTER TAU
120.

MODEL DISCUSSION: DETERMINISTIC AND PROBABILISTIC GUIDANCE REMAINS
IN GOOD AGREEMENT THROUGH TAU 72 WITH A 100NM CROSS-TRACK SPREAD IN
SOLUTIONS AT TAU 72 LENDING HIGH CONFIDENCE TO THE JTWC FORECAST
TRACK. AFTER TAU 72, DETERMINISTIC GUIDANCE DIVERGES WITH
INCREASING CROSS-TRACK AND ALONG-TRACK SPREAD PROVIDING MEDIUM
CONFIDENCE. THE SYSTEM IS NOT EXPECTED TO IMPACT HONSHU DUE TO THE
PRESENCE OF A STRONG JET OVER AND TO THE SOUTH OF HONSHU. GRADUAL
WEAKENING IS EXPECTED AFTER TAU 36 DUE TO THE STEADILY DEGRADING
ENVIRONMENT ASSOCIATED WITH THE SUBTROPICAL WESTERLIES.

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