WDPN32 PGTW 092100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 32W (FUNG-WONG) WARNING NR 023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.5N 120.3E
   INITIAL INTENSITY: 95 KTS
   GEOGRAPHIC REFERENCE: 121 NM NORTH-NORTHWEST OF MANILA,
PHILIPPINES
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 15 KTS
   SIGNIFICANT WAVE HEIGHT: 32 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
WEAKENED CONVECTIVE STRUCTURE AS TYPHOON 32W HAS BECOME
DISORGANIZED OVER THE LAST SIX HOURS. THE CIRCULATION HAS BECOME
DECAPITATED AND THE UPPER-LEVEL CONVECTION CIRCULATES WELL INTO THE
SOUTH CHINA SEA, INITIALLY CREATING A MISLEADING IMPRESSION OF THE
POSITION OF THE SYSTEM. HOWEVER, DOPPLER RADAR LOOP HAS INDICATED
THAT THE LOW-LEVEL STRUCTURE IS TUCKED MUCH CLOSER TO THE WESTERN
COAST OF LUZON. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE AFOREMENTIONED ANIMATED EIR, RADAR LOOP, AND A 091715Z
GCOM W-1 AMSR2 MICROWAVE IMAGE REVEALING THE BANDING TO BE NEARLY
ON-POINT WITH THE ASSESSED POSITION. THE INITIAL INTENSITY OF 95 KTS
IS ASSESSED WITH LOW CONFIDENCE BASED ON THE OBJECTIVE FIXES LISTED
BELOW AND AN ABSENCE OF AGENCY FIXES DUE TO THE POSITION OVER LAND.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE
   RJTD: T5.0 - 90 KTS
   CIMSS SATCON: 96 KTS AT 091713Z
   CIMSS ADT: 112 KTS AT 091730Z
   CIMSS AIDT: 96 KTS AT 091730Z
   CIMSS D-MINT: 99 KTS AT 091713Z
   CIMSS D-PRINT: 90 KTS AT 091830Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: LOW
   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 CONTINUE ON A WEST-NORTHWESTWARD
TRACK FOR THE NEXT 12 HOURS BEFORE BEGINNING TO CURVE TO A
NORTHEASTWARD TRACK AFTER TAU 48. THE SYSTEM WILL CONTINUE TO ROUND
THE NORTHEASTERN PERIPHERY OF THE SUBTROPICAL RIDGE TO THE EAST
WHILE WEAKENING AND SHALLOWING, CURVING TO AN EASTWARD TRACK AFTER
TAU 72 THAT WILL CONTINUE FOR THE REMAINDER OF THE FORECAST PERIOD.
THE ENVIRONMENT WILL WORSEN AS VERTICAL WIND SHEAR INCREASES
GRADUALLY. PARTICULARLY AFTER TAU 48, THE SYSTEM WILL BEGIN TO TRACK
UPSTREAM OF THE NORTHEAST MONSOON RESULTING IN HIGHLY UNFAVORABLE
SHEAR AND DRY AIR ENTRAINMENT INTO THE CIRCULATION. SLIGHT LAND
INTERACTION IS EXPECTED AS TY 32W TRACKS OVER NORTHERN TAIWAN AT
TAU 72 AND WILL CONTRIBUTE TO FURTHER DISRUPTION OF THE LOW-LEVEL
CIRCULATION. BY THE END OF THE FORECAST PERIOD, THE DRY AIR AND
SHEAR WILL CONTINUE TO ERODE THE CIRCULATION, LEAVING TY 32W
DISSIPATED OVER WATER AT 20KTS.

MODEL DISCUSSION: THE DETERMINISTIC MODEL GUIDANCE IS IN MODERATE
AGREEMENT UNTIL TAU 72 WITH A CROSS-TRACK SPREAD OF 136NM, HOWEVER,
THE SPREAD BEGINS TO OPEN WIDELY AFTER TY 32W CLIPS NORTHERN TAIWAN
LEADING TO VARIED MODEL INTERPRETATIONS OF WHERE THE CIRCULATION
CENTER LEADS. THE CROSS-TRACK SPREAD OPENS TO 532NM BY TAU 120 WITH
A LARGE ALONG-TRACK SPREAD AS WELL. THE ERRATIC MOTION OF MOST OF
THE VORTEX TRACKERS MAY BE INDICATIVE OF A STRUGGLE TO FIND THE
CIRCULATION AFTER TAU 96 SPECIFICALLY, AND IS SOMEWHAT REFLECTED IN
THE MODEL FIELDS AS THERE ARE ASYMMETRIC BUT CLOSED REMNANTS
DEPICTED OF 32W AT TAU 120 EMBEDDED WITHIN THE EASTERN PERIPHERY OF
THE NORTHEAST MONSOON. THE INTENSITY GUIDANCE INDICATES A MORE
GRADUAL WEAKENING OF TY 32W AS THE SYSTEM TRACKS UPSTREAM OF THE
MONSOONAL FLOW, WITH SOME CONSENSUS MEMBERS INDICATING UNUSUAL
PERIODS OF REINTENSIFICATION. THE JTWC FORECAST LIES BELOW THE
MODEL GUIDANCE DUE TO THE UNREALISTIC STANDPOINT THAT THE SYSTEM
WOULD BE ABLE TO WITHSTAND 25-30KTS OF SHEAR AFTER TAU 36 AND THE
ENTRAINMENT OF SUBSIDENT DRY AIR. 

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