WDPN32 PGTW 090900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 32W (FUNG-WONG) WARNING NR 
021//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.9N 123.2E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 129 NM EAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 42 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON
(TY) 32W (FUNG-WONG) WITH A RAGGED EYE FEATURE AND POCKETS OF
FLARING DEEP CONVECTION, MOSTLY ON THE SOUTHWESTERN QUADRANT OF THE
CIRCULATION. ENVIRONMENTAL ANALYSIS DEPICTS A MARGINALLY FAVORABLE
ENVIRONMENT WITH STRONG OUTFLOW, WARM SEA SURFACE TEMPERATURES (28
C TO 29 C), AND MODERATE VERTICAL WIND SHEAR (15-20 KTS) OFFSET BY
THE DRY AIR SURROUNDING THE SYSTEM, THOUGH NOT YET ENTRAINED INTO
THE CENTER OF THE VORTEX. OVERALL THERE HAS BEEN LITTLE CHANGE IN
THE STRUCTURE OF THE SYSTEM OVER THE PAST 6 HOURS. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON EIR IMAGERY AND
AGENCY FIXES. THE INITIAL INTENSITY OF 115 KTS IS ASSESSED WITH
HIGH CONFIDENCE BASED ON INTERPOLATION OF THE 090138Z METOP-C
SCATTEROMETER DATA AND SUBJECTIVE ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: 090138Z METOP-C SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT BETWEEN
SUBTROPICAL RIDGES TO THE NORTHEAST AND NORTHWEST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T5.5 - 102 KTS
   CIMSS SATCON: 131 KTS AT 090530Z
   CIMSS ADT: 137 KTS AT 090540Z
   CIMSS AIDT: 121 KTS AT 090540Z
   CIMSS D-MINT: 119 KTS AT 090440Z
   CIMSS D-PRINT: 125 KTS AT 090610Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: HIGH

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TY 32W IS FORECAST TO MAKE LANDFALL SOUTH OF
BALER BAY, PHILIPPINES OVER THE NEXT 12 HOURS WITH A SIGNIFICANT
WEAKENING OF THE SYSTEM STRUCTURE EXPECTED DUE TO TOPOGRAPHIC
INTERACTIONS. FUNG-WONG WILL THEN ENTER THE SOUTH CHINA SEA, LIKELY
PASSING NORTH OF SANTIAGO ISLAND, PHILIPPINES, THOUGH SOME
UNCERTAINTY REMAINS DUE THE INFLUENCE OF FRICTIONAL EFFECTS OF THE
TERRAIN. WEAKENING STEERING PATTERN AFTER TAU 24 WILL ALLOW THE
TRACK OF FUNG-WONG TO SHIFT TO NORTHWARD AND THEN NORTHEASTWARD,
TOWARDS TAIWAN. DURING THIS SHIFT THE SYSTEM WILL ADD DRY AIR
ENTRAINMENT TO ITS LIST OF INHIBITING FACTORS, WHICH WILL STALL THE
SYSTEM OUT, FORCING IT TO REORGANIZE BUT CHANGE A LITTLE MORE UNTIL
THE SHIFT TO THE NORTHEAST AROUND TAU 48. POST TAU 48 INCREASING
VERTICAL WIND SHEAR AND COOLER SEA SURFACE TEMPERATURES WILL
INITIATE A MORE SIGNIFICANT WEAKENING TREND THAT WILL CONTINUE FOR
THE REMAINDER OF THE FORECAST PERIOD AIDED BY LANDFALL OVER THE
SOUTHWESTERN PORTION OF TAIWAN AFTER TAU 72. TY 32W WILL THAN
TRANSIT OVER THE CENTRAL PORTION OF TAIWAN EMERGING OVER THE EAST
CHINA SEA AS A SIGNIFICANTLY WEAKER CIRCULATION AND WILL FULLY
DISSIPATE OVER WATER SHORTLY AFTER TAU 120. 

MODEL DISCUSSION: THERE IS A 60 NM CROSS TRACK SPREAD IN MODEL
GUIDANCE THROUGH TAU 36. AFTERWARDS THE SPREAD INCREASES UP TO 170
NM FOR THE REMAINDER OF THE FORECAST PERIOD. THERE HAS BEEN SOME
IMPROVEMENT ON THE SPREAD FOR THE FORECASTED CURVING OF THE SYSTEM.
GFS REJOINED ITS PEERS WITH THE GUIDANCE SHOWING A NORTHWARD, THEN
NORTHEASTWARD TRACK OVER TAIWAN POSITIONED BETWEEN ECMWF, WHICH
COVERS THE WESTERNMOST FORECAST AND NAVGEM, WHICH REFLECTS THE
EASTERNMOST TRACK. SOME CHANGE IS EXPECTED TO THESE DEPICTIONS AS
THE SYSTEM IS NEARING LUZON. LANDFALL OVER THE SOUTHWESTERN PORTION
OF TAIWAN IS DEPICTED AFTER TAU 72 WITH THE MULTI-MODEL CONSENSUS,
FOLLOWED BY THE SYSTEM TRANSITING OVER THE CENTER OF THE ISLAND.
THE JTWC FORECAST TRACK IS PLACED CLOSE TO THE MULTI-MODEL
CONSENSUS WITH MEDIUM CONFIDENCE DUE TO EXPECTED POSITION
UNCERTAINTY AFTER LANDFALL OVER LUZON AND THE LARGER SPREAD
REFLECTED AFTER LANDFALL OVER TAIWAN. INTENSITY SPREAD INCREASES UP
TO 50 KTS AS THE MODELS ATTEMPT TO RESOLVE THE CHANGE IN STEERING
INFLUENCE AND EFFECTS OF LANDFALL WHILE TY FUNG-WONG REORGANIZES IN
THE SOUTH CHINA SEA (SCS). MAJORITY OF THE MEMBERS ATTEMPT TO SHOW
SOME STRENGTHENING OVER THE SCS DESPITE THE SYSTEM TRACKING FURTHER
INTO INHIBITING DRY AIR, LIKELY DUE TO EXPECTED INCREASE IN UPPER
LEVEL DIVERGENCE. THE MULTI-MODEL CONSENSUS DOES NOT REFLECT THE
WEAKENING TREND PROPERLY AFTER TAU 72, DUE TO STATISTICAL-DYNAMICAL
MODELS ASSESSING DISSIPATION OF THE CIRCULATION. AS A RESULT,
CONSENSUS AVERAGE IS HIGHER THAN EXPECTED. THEREFORE THE JTWC
FORECAST IS PLACED NEAR TO THE MULTI-MODEL CONSENSUS THROUGH TAU 72
AND THEN REFLECTS INTENSITIES BELOW THE CONSENSUS, MORE
REPRESENTATIVE OF HWRF AND GFS, FOR THE REMAINDER OF THE FORECAST
PERIOD.  

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   TRACK 72-120 HR: MEDIUM
   INTENSITY 00-72 HR: HIGH
   INTENSITY 72-120 HR: MEDIUM//
NNNN