WDPN33 PGTW 270900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 25W (NEOGURI) WARNING NR 
036//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 31.9N 157.1E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 490 NM NORTH-NORTHEAST OF MINAMI TORI
SHIMA
   MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 26 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
STORM (TS) 25W (NEOGURI) ON A NORTHEASTWARD TRACK, UNDER A PRIMARY
INFLUENCE FROM A SUBTROPICAL RIDGE (STR) TO THE EAST-NORTHEAST. WHILE 
THE SYSTEM IS APPROACHING THE AXIS OF THE RIDGE, IT STILL REMAINS 
WITHIN A MARGINALLY FAVORABLE, TROPICAL ENVIRONMENT CHARACTERIZED BY 
LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS), RELATIVELY WARM (27-28 C) 
SEA SURFACE TEMPERATURES (SST) AND STRONG POLEWARD OUTFLOW. THE 
VORTEX REMAINS FAIRLY SYMMETRICAL AND THE SYSTEM IS MANAGING TO 
MAINTAIN A MOIST CORE, DESPITE SURROUNDING DRY AIR. THE INITIAL 
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON ANIMATED VISIBLE 
SATELLITE IMAGERY SHOWING DISTINCT, CURVED CONVECTIVE WRAPPING INTO 
THE PREDOMINANTLY OBSCURED LOW-LEVEL CIRCULATION CENTER (LLCC). THE
INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON THE DVORAK AGENCY FIXES LISTED BELOW. AUTOMATED INTENSITY
AIDS ARE MORE CONSERVATIVE THAN SUBJECTIVE DVORAK INTENSITY GUIDANCE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST-NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 53 KTS AT 270310Z
   CIMSS ADT: 45 KTS AT 270530Z
   CIMSS AIDT: 43 KTS AT 270530Z
   CIMSS D-MINT: 54 KTS AT 270219Z
   CIMSS D-PRINT: 56 KTS AT 270630Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

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: TS 25W IS FORECAST TO CONTINUE ITS
NORTHEASTWARD TRACK UNDER THE INFLUENCE OF A STR TO THE
EAST-NORTHEAST THROUGHOUT ITS TROPICAL LIFECYCLE PHASE. INTENSITY
GUIDANCE AND ENVIRONMENTAL ANALYSIS INDICATES THAT THE SYSTEM WILL
SLIGHTLY INTENSIFY OVER THE NEXT 24 HOURS. AROUND TAU 36 HOWEVER,
TS NEOGURI WILL ENCOUNTER SIGNIFICANTLY COOLER (23-24 C) SSTS, AS
WELL AS DRASTICALLY INCREASING VWS ASSOCIATED WITH AN APPROACHING
UPPER-LEVEL SHORTWAVE TROUGH. SIMULTANEOUSLY, THE SYSTEM IS
EXPECTED TO BEGIN ITS EXTRATROPICAL TRANSITION, WHICH IS EXPECTED
TO CONCLUDE AROUND TAU 48. COLD SSTS, INJECTION OF DRY AIR AND
INCREASING VWS WILL RESULT IN A WEAKENING TREND TOWARD THE END OF
THE FORECAST PERIOD.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT THROUGHOUT THE FORECAST PERIOD, AS WITNESSED BY A
CROSS-TRACK SPREAD OF 70 NM AT TAU 48, WITH THE EXCLUSION OF THE
ONLY OUTLIER - JGSM, WHICH SUGGESTS A MORE POLEWARD TRACK.
INTENSITY GUIDANCE ALSO REMAINS IN GOOD AGREEMENT, WITH SOME
UNCERTAINTY ASSOCIATED WITH THE INTENSIFICATION RATE OVER THE NEXT
24 HOURS, AS IDENTIFIED BY A 45-50 KTS PEAK INTENSITY SPREAD
BETWEEN THE MOST CONSERVATIVE DETERMINISTIC GFS AND STATISTICAL-
DYNAMICAL MODELS, JOINED BY SOME OF THE RAPID INTENSIFICATION (RI) 
AIDS, AS WELL AS HAFS, WHICH ALL PREDICT A HIGHER INTENSITY PEAK. 
JTWC OFFICIAL FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS 
AND IS THEREFORE ASSESSED WITH MEDIUM CONFIDENCE.

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