WDPN32 PGTW 252100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 08W (HIGOS) WARNING NR 
014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.4N 134.1E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 423 NM SOUTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 17 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A FULLY
OBSCURED LOW-LEVEL CIRCULATION CENTER (LLCC) OF TROPICAL STORM (TS)
08W (HIGOS). CENTRAL DENSE OVERCAST (CDO) FEATURE IS FRAGMENTED,
BUT PERSISTENT, INDICATING CONTINUOUS DEVELOPMENT CONSISTENT WITH
SLIGHT INTENSIFICATION. THE INITIAL POSITION IS PLACED WITH MEDIUM
CONFIDENCE BASED ON UPPER-LEVEL CLOUD TOPS TURNING IN SHORTWAVE
INFRARED IMAGERY, CORROBORATED BY GFS LOW PRESSURE CENTER POSITION
AND THE AGENCY FIXES. THE INITIAL INTENSITY OF 50 KTS IS ASSESSED 
WITH HIGH CONFIDENCE BASED ON A COMBINATION OF AUTOMATED AND 
SUBJECTIVE FIXES LISTED BELOW. ENVIRONMENTAL ANALYSIS REVEALS WARM
(29-30 C) SEA SURFACE TEMPERATURES (SST), WEAK EQUATORWARD OUTFLOW,
LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS) AND DRY AIR SURROUNDING
THE IMMEDIATE VICINITY OF THE SYSTEM. AS SUCH, THE CONDITIONS FOR
TROPICAL DEVELOPMENT REMAIN MARGINALLY FAVORABLE.

INITIAL WIND RADII BASIS: A 251426Z OCEANSAT-3 SCATTEROMETER DATA

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) CENTERED TO THE
NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T3.0 - 45 KTS
   CIMSS SATCON: 46 KTS AT Z
   CIMSS ADT: 55 KTS AT Z
   CIMSS AIDT: 47 KTS AT Z
   CIMSS D-MINT: 45 KTS AT 251651Z
   CIMSS D-PRINT: 50 KTS AT 251830Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: WEAK EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: HIGH
   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 08W IS FORECAST TO CONTINUE ACCELERATING,
WHILE IT APPROACHES THE AXIS OF A STR CURRENTLY CENTERED TO THE
NORTHEAST. AFTER TAU 12, THE SYSTEM IS EXPECTED TO BEGIN TRACKING
NORTHEASTWARD, WHILE TRANSITING ALONG THE NORTHWESTERN PERIPHERY OF
THE RIDGE. PRIOR TO RECURVATURE, SLIGHT INTENSIFICATION IS EXPECTED,
WITH THE SYSTEM REACHING 55 KTS. AROUND TAU 24, THE EXTRATROPICAL
TRANSITION WILL BEGIN AS TS 08W STARTS INTERACTING WITH THE 
BAROCLINIC ZONE TO THE NORTH. THE LLCC WILL BE POSITIONED DIRECTLY
UNDERNEATH THE SOUTHERN PORTION OF A SUBTROPICAL JET, RESULTING IN
DRAMATIC INCREASE IN THE VERTICAL WIND SHEAR. THE ETT IS EXPECTED
TO COMPLETE BY TAU 36, WHILE THE CIRCULATION LIKELY OPENING UP
INTO A TROUGH.

MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN FAIR
AGREEMENT IN REGARD TO THE RECURVATURE SCENARIO AND THE SYSTEM
TRACKING ALONG THE PERIPHERY OF A STR, WHILE ACCELERATING. GALWEM
IS THE PRIMARY OUTLIER, AS IT SUGGESTS A WIDER RECURVATURE AND TRACK 
CLOSER TO SHIKOKU, JAPAN. THE CROSS TRACK SPREAD BETWEEN TAUS 12 AND 
24 EXPANDS FROM A CONSENSUS MEAN OF 120 NM EXCLUDING GALWEM, TO 220 
NM WITH ALL MODELS INCLUDED. ADDITIONALLY, SOME GUIDANCE MODELS 
(NAVGEM AND JGSM) LOSE THE VORTEX AFTER TAU 12. THEREFORE, THE 
OFFICIAL JTWC TRACK PREDICTION IS PLACED CLOSE TO THE MULTI-MODEL 
CONSENSUS WITH MEDIUM CONFIDENCE. INTENSITY FORECAST IS ASSESSED WITH 
HIGH CONFIDENCE, AS ALL MODELS INDICATE POTENTIAL FOR MINOR 
INTENSIFICATION OVER THE NEXT 12-24 HOURS, FOLLOWED BY SLOW AND 
STEADY TERMINAL WEAKENING CONSISTENT WITH EXTRATROPICAL TRANSITION.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   INTENSITY 00-72 HR: HIGH//
NNNN