WDPN31 PGTW 080300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W (KOINU) WARNING NR 035//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.5N 114.6E
   INITIAL INTENSITY: 85 KTS
   GEOGRAPHIC REFERENCE: 53 NM SOUTH-SOUTHEAST OF HONG KONG
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 26 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
AS INDICATED IN RECENT ANIMATED RADAR IMAGERY, THE EYEWALL 
REPLACEMENT CYCLE (ERC) APPEARS TO BE NEAR COMPLETE. IMAGERY NOW 
DEPICTS A WEAK REMNANT OF THE INNER EYEWALL WITHIN A DOMINANT OUTER 
EYEWALL WITH A 20 NM DIAMETER. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY (MSI) DEPICTS A CLOUD-FILLED EYE WITH AN OVERSHOOTING TOP 
EVIDENT JUST NORTH OF THE CENTER. BASED ON THE MSI AND RADAR IMAGERY, 
THERE IS HIGH CONFIDENCE IN THE INITIAL POSITION. THE SYSTEM HAS 
WEAKENED SIGNIFICANTLY AND IS NOW ASSESSED AT 85 KNOTS BASED ON THE 
AGENCY DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM 77 TO 90 KTS. 
A VERY RECENT 072210Z RCM-3 SAR IMAGE ALSO INDICATES MAXIMUM WINDS OF 
81 KNOTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: COMPETING STEERING INFLUENCE WITH A
DEEP-LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE EAST AND A
WEAK STR POSITIONED TO THE WEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   RJTD: T5.0 - 90 KTS
   KNES: T4.5 - 77 KTS
   DEMS: T4.5 - 77 KTS
   CIMSS ADT: 61 KTS AT 072330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL
   OTHER FACTORS: INTERACTION WITH LAND

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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 14W IS FORECAST TO TRACK SLOWLY WESTWARD
THROUGH TAU 12 WITHIN THE COMPETING STEERING ENVIRONMENT WITH
GRADUAL WEAKENING AS THE INNER EYEWALL ERODES COMPLETELY AND THE
ERC COMPLETES. AFTER TAU 12, A WEAK EXTENSION OF THE LOW- TO
MID-LEVEL STR IS FORECAST TO BUILD TO THE NORTH, WHICH WILL
ACCELERATE THE SYSTEM WEST-SOUTHWESTWARD TO SOUTHWESTWARD THROUGH
THE FORECAST PERIOD. AS THE SYSTEM SKIRTS THE SOUTHEAST COAST OF
CHINA AND TRACKS OVER HAINAN ISLAND, SIGNIFICANT WEAKENING WILL
OCCUR WITH EVENTUAL DISSIPATION NEAR TAU 120 AS TY 14W TRACKS INTO
VIETNAM AND LAOS.       

MODEL DISCUSSION: DETERMINISTIC GUIDANCE REMAINS IN FAIR AGREEMENT
LENDING MEDIUM CONFIDENCE TO THE JTWC TRACK FORECAST THROUGH TAU
120. THE 071800Z GFS AND ECMWF ENSEMBLES (GEFS AND EPS) ARE ALSO IN
FAIR AGREEMENT AND SHOW RAPID 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//
NNNN