WDPN33 PGTW 250900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (NEOGURI) WARNING NR 028//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 33.0N 156.1E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 825 NM EAST OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A
SLOW-MOVING SYSTEM, WITH LOW-LEVEL CLOUDS TIGHTLY WRAPPING INTO THE
OBSCURED LOW-LEVEL CIRCULATION CENTER (LLCC). ADDITIONALLY, THE 
PERSISTENT
CENTRAL CONVECTION HAS DEEPENED AND COOLED SIGNIFICANTLY IN THE
PAST 6 HOURS. ENVIRONMENTAL ANALYSIS INDICATES THE SYSTEM IS
CURRENTLY IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY LOW VERTICAL
WIND SHEAR (10-15 KTS), WARM SEA SURFACE TEMPERATURES (28-29 C),
AND STRONG POLEWARD OUTFLOW. THE INITIAL POSITION IS PLACED WITH
MEDIUM CONFIDENCE BASED ON THE OBSCURED LLCC IN ANIMATED MSI. THE
INITIAL INTENSITY OF 70 KTS IS ASSESSED WITH LOW CONFIDENCE
BASED PRIMARILY ON THE AGENCY DVORAK INTENSITY ESTIMATES. CIMSS 
OBJECTIVE INTENSITY ESTIMATES ARE ANALYZED TO BE TOO LOW DUE TO THE 
SMALL CONVECTIVE FOOTPRINT.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT BETWEEN
TWO SUBTROPICAL RIDGES (STR) OF EQUAL STRENGTH POSITIONED TO THE
EAST AND WEST OF THE SYSTEM

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T3.0 - 45 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 52 KTS AT 250257Z
   CIMSS ADT: 33 KTS AT 250540Z
   CIMSS AIDT: 40 KTS AT 250540Z
   CIMSS D-PRINT: 52 KTS AT 250610Z

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

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THE TRACK FORECAST HAS CHANGED FROM
THE PREVIOUS FORECAST, SHIFTING TAU 12-48 TO THE SOUTHEAST,
CAPTURING A FORECASTED LOOP IN STORM MOTION

FORECAST DISCUSSION: TYPHOON 25W IS EXPECTED TO CONTINUE ITS RECENT
SOUTHWESTWARD MOTION THROUGH TAU 24, WHEN IT WILL SLOWLY MAKE AN
EASTWARD TURN TO LOOP OVER ITS PREVIOUS TRACK BETWEEN TAUS 36-48.
WHILE THE STORM IS QUASI-STATIONARY, ERRATIC MOTION NOT REFLECTED
IN THE FORECAST MAY OCCUR. AFTER TAU 48, 25W WILL SIGNIFICANTLY
ACCELERATE AS IT ENTERS UNDER THE INFLUENCE OF THE UPPER-LEVEL JET 
AND 
BEGINS EXTRATROPICAL TRANSITION (ETT). ETT IS EXPECTED TO
BE COMPLETE BY TAU 72. REGARDING INTENSITY, 25W IS FORECAST TO
APPROXIMATELY MAINTAIN INTENSITY THROUGHOUT THE FORECAST PERIOD,
WITH A MINOR WEAKENING BETWEEN TAUS 12-24, LIKELY DUE TO THE
UPWELLING OF COOL WATER AS THE STORM REMAINS QUASI-STATIONARY AND
SLIGHTLY INCREASING VERTICAL WIND SHEAR (15-20 KTS). INTENSITY IS 
FORECAST TO INCREASE TO 75 KTS AT TAUS 48-72 AS 25W IS PICKED UP BY
THE JET AND POLEWARD OUTFLOW BECOMES EVEN STRONGER.

MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT THROUGH TAU 24, WITH ALL JTWC CONSENSUS MODELS HOLDING
25W ON A SOUTHWESTWARD TRACK. GUIDANCE DEVIATES AFTER TAU 24, WITH
GFS PREDICTING 25W WILL DOUBLE-BACK OVER ITSELF, WHILE ECMWF,
UKMET, AND JGSM SHOW 25W TRAVELING IN A LOOP. THE DISCREPANCY
BETWEEN TRACK MODEL GUIDANCE LENDS UNCERTAINTY TO THE TAU 0-36
FORECAST, CONTRIBUTING TO THE OVERALL MEDIUM TRACK FORECAST
CONFIDENCE. INTENSITY GUIDANCE IS SLIGHTLY SPLIT, WITH COAMPS-TC AND 
GFS DEPICTING MARGINAL INTENSIFICATION FROM TAU 24 THROUGH TAU 60 
WHILE HAFS-A SUGGESTS EXTREME INTENSIFICATION TO NEAR 115 KTS. THE 
JTWC INTENSITY FORECAST IS PLACED MORE IN LINE WITH GFS AND COAMPS-TC 
WITH LOW CONFIDENCE.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   INTENSITY 00-72 HR: LOW//
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