WDPN32 PGTW 072100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 32W (FUNG-WONG) WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.2N 133.8E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 252 NM NORTH-NORTHWEST OF KAYANGEL
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS BUILDING
CONVECTION AND OVERSHOOTING CLOUD TOPS AS TYPHOON (TY) 32W HAS
CONTINUED TO INTENSIFY OVER THE LAST SIX HOURS. THE STRUCTURE OF
THE SYSTEM REMAINS BROAD AND SLIGHTLY DISORGANIZED WITH BANDING
STRUGGLING TO CONSOLIDATE AND TIGHTEN AROUND THE LOW-LEVEL
CIRCULATION CENTER (LLCC). OUTFLOW ALOFT REMAINS EXPANSIVE RADIALLY
WITH A POINT SOURCE POSITIONED JUST NORTHEAST OF THE
UPPER-LEVEL CIRCULATION. THE DISORGANIZED STRUCTURE IS AFFIRMED BY
A 071659Z NOAA-20 ATMS 89GHZ IMAGE DEPICTING BROKEN UPPER-LEVEL
BANDING. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE
BASED ON THE AFOREMENTIONED ANIMATED EIR AND EXTRAPOLATION FROM THE
ATMS IMAGE DUE TO THE DIFFICULTY IDENTIFYING THE LOW-LEVEL POSITION
HIDDEN BENEATH THE DEEP CONVECTION. THE INITIAL INTENSITY OF 70 KTS
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY AND
OBJECTIVE FIXES LISTED BELOW, NOTING THAT THERE MAY BE A SLIGHT LOW
BIAS IN DVORAK INTENSITIES DUE TO THE LARGE DIAMETER OF THE SYSTEM.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: A COMPETING STEERING ENVIRONMENT
BETWEEN A SUBTROPICAL RIDGE TO THE NORTHEAST AND NORTHWEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T4.5 - 77 KTS
   CIMSS SATCON: 69 KTS AT 071700Z
   CIMSS ADT: 57 KTS AT 071730Z
   CIMSS AIDT: 59 KTS AT 071730Z
   CIMSS D-PRINT: 71 KTS AT 071800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: TY 32W WILL REMAIN BETWEEN A COMPETING
STEERING TWO SUBTROPICAL RIDGES TO THE NORTHEAST AND NORTHWEST FOR
THE NEXT 48 HOURS, DRIVING THE SYSTEM ALONG A WEST-NORTHWESTWARD
TRACK. AFTERWARDS, THE NORTHWESTERN RIDGE WILL WEAKEN, ALLOWING TY
32W TO CURVE ALONG THE NORTHWESTERN RIDGE FROM TAU 72 THROUGH TAU
96, ENDING ON NORTHEASTWARD TRACK BY TAU 120. THE ENVIRONMENT WILL
REMAIN HIGHLY FAVORABLE FOR DEVELOPMENT FOR THE NEXT 36 HOURS WHILE
THE SYSTEM REMAINS OVER WATER IN WARM SEA SURFACE TEMPERATURES, LOW
VERTICAL WIND SHEAR, AND EXPANSIVE UPPER-LEVEL DIFFLUENCE.
WEAKENING WILL OCCUR AFTER TY 32W MAKES LANDFALL AT TAU 48 ON LUZON
DUE TO TOPOGRAPHIC INTERACTION WITH THE CORDILLERA CENTRAL MOUNTAIN
RANGE. WEAKENING WILL CONTINUE AFTER TY 32W PASSES INTO THE SOUTH
CHINA SEA DUE TO HIGH VERTICAL WIND SHEAR ABOVE 25KTS AS THE
TYPHOON TRACK UPSTREAM INTO THE CLIMATOLOGICAL COLD SURGE,
INGESTING SUBSIDENT DRY AIR INTO THE CIRCULATION. WEAKENING WILL
CONTINUE AT TAU 120 WHEN THE FINAL POSITION IS OVER MAINLAND
TAIWAN.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
AND CONSISTENT IN THE CROSS-TRACK GUIDANCE, BUT HAS A 420
ALONG-TRACK SPREAD AT TAU 120 BETWEEN GFS (SLOWEST) AND GALWEM
(FASTEST). THE SPREAD STARTS AT TAU 72 ONCE TY 32W BEGINS TO CURVE
AROUND THE SUBTROPICAL RIDGE. THE INTENSITY GUIDANCE GIVES A STRONG
RAPID INTENSIFICATION SIGNAL DESPITE THE LARGE SIZE OF THE TYPHOON
WITH THE JTWC SHIPS GUIDANCE INDICATING RAPID INTENSIFICATION,
HAFS-A, HWRF, AND COAMPS-TC INDICATING RAPID INTENSIFICATION. THE
SPREAD OF PEAK INTENSITIES LIES AT TAU 36 FROM 80-125KTS.

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