WDPN31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (IN-FA) WARNING NR 030//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.8N 125.0E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 183 NM WEST-SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TY 09W HAS CONTINUED TO SLOWLY WEAKEN AS INDICATED IN ANIMATED
ENHANCED INFRARED (EIR) SATELLITE IMAGERY, WHICH DEPICTS DECAYING
DEEP CONVECTION AROUND A LARGE, 55NM EYE. THE INITIAL POSITION IS
PLACED WITH MEDIUM CONFIDENCE BASED ON A 231120Z GMI 89GHZ COLOR
COMPOSITE MICROWAVE IMAGE, ANIMATED RADAR IMAGERY AND A 231200Z
RJTD RADAR FIX. THE GMI IMAGE SHOWS A NARROW, SOMEWHAT FRAGMENTED
EYEWALL WITH SPIRAL BANDING WRAPPING INTO THE CENTER. THE INITIAL
INTENSITY OF 70 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE
PGTW AND RJTD DVORAK DATA-T (T4.0) AND CURRENT INTENSITY (4.5)
ESTIMATES AS WELL AS THE LATEST SATCON ESTIMATE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: THE SOUTHWESTERN PERIPHERY OF A
DEEP-LAYERED SUBTROPICAL RIDGE (STR) CENTERED JUST OFF THE EAST
COAST OF THE KOREAN PENINSULA.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 67 KTS AT 231026Z
   CIMSS ADT: 55 KTS AT 231140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TY 09W IS TRACKING SLOWLY ALONG THE
SOUTHWESTERN PERIPHERY OF THE STR AND IS FORECAST TO TRACK
NORTH-NORTHWESTWARD TO NORTHWESTWARD THROUGH TAU 36 THEN GRADUALLY
TURN WESTWARD UNDER AN EXTENSION OF THE STR TO THE NORTH. SLIGHT
INTENSIFICATION TO 75 KNOTS IS EXPECTED IN THE SHORT-TERM THEN
GRADUAL WEAKENING AS TY 09W APPROACHES THE CHINA COAST. NEAR TAU
72, THE SYSTEM WILL SLOW AS A MAJOR SHORTWAVE TROUGH DIGS OVER
EASTERN CHINA AND WILL TRACK OVERLAND LEADING TO RAPID WEAKENING
AND EVENTUAL DISSIPATION DUE TO INTERACTION WITH LAND.     

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN BETTER AGREEMENT
SUPPORTING THE JTWC FORECAST TRACK WITH MEDIUM CONFIDENCE. THE
ECMWF ENSEMBLE (EPS) ALSO SUPPORTS THE JTWC TRACK FORECAST WITH A
HIGH PROBABILITY. THERE IS MEDIUM CONFIDENCE IN THE JTWC INTENSITY
FORECAST WITH THE BULK OF THE INTENSITY GUIDANCE INDICATING A
SLIGHT INTENSIFICATION THEN STEADY WEAKENING AFTER TAU 24.


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