WDPN32 PGTW 120900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 32W (FUNG-WONG) WARNING 
NR 033//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.8N 119.8E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 521 NM WEST-SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 21 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
STORM 32W (FUNG-WONG) WITH A COMPLETELY EXPOSED LOW-LEVEL
CIRCULATION CENTER (LLCC) THAT IS PULLING IN A BELT OF
STRATOCUMULUS CLOUDS INTO THE CORE. A 120536Z AMSR2 IMAGE SUITE
REVEALED THAT THE LLCC REMAINS WELL-DEFINED WITH DEEP CONVECTION
CONFINED TO A SMALL AREA WITHIN THE FAR NORTHWESTERN PERIPHERY. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE
EXPOSED LLCC IN ANIMATED MSI AND THE AMSR2 IMAGE. A 120215Z METOP-C
ASCAT PASS SHOWED 45 KNOT NORTHERLY WINDS WITHIN THE NORTHWESTERN
QUADRANT, SUPPORTING THE INITIAL INTENSITY ESTIMATE. ENVIRONMENTAL
ANALYSIS INDICATES THAT 32W IS IN A HIGHLY UNFAVORABLE ENVIRONMENT
CHARACTERIZED BY MODERATE POLEWARD OUTFLOW ALOFT, HIGH (20-25 KTS)
SOUTHERLY VERTICAL WIND SHEAR, SIGNIFICANT DRY AIR ENTRAINMENT, AND
WARM (27-28 C) SEA SURFACE TEMPERATURES.

INITIAL WIND RADII BASIS: 120215Z METOP-C ASCAT SCATTEROMETER DATA

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE CENTERED TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.0 - 30 KTS
   KNES: T1.5 - 25 KTS
   DEMS: T2.5 - 35 KTS
   CIMSS SATCON: 38 KTS AT 120526Z
   CIMSS ADT: 31 KTS AT 120600Z
   CIMSS AIDT: 32 KTS AT 120600Z
   CIMSS D-MINT: 32 KTS AT 120526Z
   CIMSS D-PRINT: 33 KTS AT 120600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 20-25 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE POLEWARD
   OTHER FACTORS: SIGNIFICANT DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   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 32W IS FORECAST TO CONTINUE ROUNDING THE
WESTERN EXTENT OF THE SUBTROPICAL RIDGE THROUGH TAU 36 WITH A
GENERALLY NORTHEASTWARD TRACK. LANDFALL WITHIN SOUTHERN TAIWAN,
NEAR KAOHSIUNG, IS EXPECTED TO OCCUR WITHIN THE NEXT 6 HOURS. THE
SYSTEM WILL THEN SKIRT ACROSS THE SOUTHERN COAST AND EMERGE BACK
OVER WATER NEAR TAU 12. THE BRIEF TERRAIN INTERACTION AND CONTINUED
DRY AIR ENTRAINMENT IS FORECAST TO WEAKEN 32W AS IT APPROACHES THE
SOUTHERN RYUKYU ISLANDS. AFTER TAU 12, 32W WILL BEGIN TO WRAP IN
THE NORTHWESTERLY SURGE WINDS AGAIN, ALLOWING THE SYSTEM TO
MAINTAIN INTENSITY THROUGH TAU 24. 32W IS THEN EXPECTED TO QUICKLY
STRETCH AND BECOME ILL-DEFINED AS IT BECOMES ABSORBED INTO THE
FORMING FRONTAL BOUNDARY. THIS MERGE WITH THE FRONTAL BOUNDARY IS
EXPECTED TO COMPLETE AROUND TAU 48, MARKING THE POINT WHERE 32W IS
STATED TO BE DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE. A FINAL
INTENSITY OF 30 KTS IS REPRESENTATIVE OF THE BACKGROUND WINDS
ASSOCIATED WITH THE NORTHEASTERLY SURGE AS THE VORTEX OF 32W
COMPLETELY WASHES OUT. 

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN MODERATE
AGREEMENT THROUGH TAU 36. ONE MAJOR OUTLIER IS GALWEM, WHICH
DEPICTS A MUCH FASTER TRACK SPEED THAN THE REMAINDER OF GUIDANCE.
DISCOUNTING GALWEM, THERE IS A 130 NM CROSS-TRACK SPREAD AT TAU 36.
AFTER TAU 36, MODELS QUICKLY DIVERGE DUE TO DIFFERING INTERACTIONS
WITH THE FRONTAL BOUNDARY. SOME MODELS TRACK THE VORTEX
SOUTHEASTWARD WHILE OTHERS CONTINUE ON A EAST-NORTHEASTWARD TRACK.
THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE CONSENSUS THROUGH
TAU 36 AND THEN CLOSER TO THE ECMWF AN AI MODELS THROUGH TAU 48
WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE AGREES ON WEAKENING
THROUGH TAU 12, BUT THEN DISAGREES AFTERWARD. SOME MODELS DEPICT
CONSISTENT WEAKENING WHILE OTHERS DEPICT SLIGHT INTENSIFICATION
AROUND TAU 24, LIKELY ACCOUNTING FOR THE BACKGROUND SURGE FLOW. THE
JTWC INTENSITY FORECAST IS PLACED SLIGHTLY BELOW THE CONSENSUS FROM
TAU 12 ONWARD IN AN ATTEMPT TO ACCOUNT FOR THE WINDS PRIMARILY
ASSOCIATED WITH 32W.

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