WDPN32 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 32W (FUNG-WONG) WARNING NR 
014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 11.9N 135.4E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 856 NM EAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON
32W (FUNG-WONG) WITH TIGHTLY CURVED CONVECTIVE BANDING AND DEFINED
CIRRUS FILAMENTS EXPANDING OUTWARD. THE SYSTEM HAS CONTINUED TO
CONSOLIDATE OVER THE PAST 6 HOURS AND DEEP CONVECTION IS NOW
STARTING TO FORM RIGHT ALONG THE EDGES OF THE LOW-LEVEL CIRCULATION
CENTER (LLCC). A 070921Z F16 SSMIS 91 GHZ MICROWAVE IMAGE REVEALED
A PROMINENT CONVECTIVE BAND THAT IS NOW EXTENDING ALL THE WAY FROM
THE WESTERN TO THE EASTERN PERIPHERY OF THE CIRCULATION. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EIR
IMAGERY SHOWING THE EXPOSED LOW-LEVEL CLOUD LINES WITHIN THE CORE
OF THE VORTEX. THE INITIAL INTENSITY OF 65 KTS IS ASSESSED WITH
MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK FIXES AND CIMSS
OBJECTIVE INTENSITY ESTIMATES LISTED BELOW. ENVIRONMENTAL ANALYSIS
INDICATES THAT 32W IS IN A HIGHLY FAVORABLE ENVIRONMENT
CHARACTERIZED BY STRONG RADIAL OUTFLOW ALOFT, LOW (5-10 KTS)
VERTICAL WIND SHEAR, AND WARM (29-30 C) SEA SURFACE TEMPERATURES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF AN EXTENSION
OF A SUBTROPICAL RIDGE (STR) CENTERED FAR TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 57 KTS AT 071130Z
   CIMSS ADT: 53 KTS AT 071200Z
   CIMSS AIDT: 62 KTS AT 071200Z
   CIMSS D-MINT: 62 KTS AT 070907Z
   CIMSS D-PRINT: 62 KTS AT 071200Z

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

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: 32W IS FORECAST TO TRACK WEST-NORTHWESTWARD
UNDER THE INFLUENCE OF A BUILDING STR TO THE NORTHEAST. THIS RIDGE
IS EXPECTED BREAK OFF FROM THE LARGER RIDGE FURTHER NORTHEAST NEAR
TAU 24 DUE TO A PASSING UPPER-LEVEL TROUGH. 32W WILL TRACK ALONG
THE SOUTHWESTERN PERIPHERY OF THE STR THROUGH TAU 72. LANDFALL
ALONG THE EASTERN COAST OF LUZON IS FORECAST TO OCCUR JUST AFTER
TAU 48, SOUTH OF CASIGURAN. THE SYSTEM WILL THEN EMERGE WITHIN THE
SOUTH CHINA SEA AND BEGIN TO ROUND THE WESTERN EXTENT OF THE STR. A 
NORTHWARD TURN IS EXPECTED TO COMMENCE NEAR TAU 72 WITH RATHER SLOW 
TRACKS SPEEDS DUE TO COMPETING STEERING WITH A SEPARATE STR THAT WILL 
BE CENTERED OVER HAINAN. A FINAL LANDFALL IS EXPECTED TO OCCUR WITHIN 
SOUTHERN TAIWAN RIGHT AROUND TAU 120. IN TERMS OF INTENSITY, 32W IS 
FORECAST TO RAPIDLY INTENSIFY THROUGH TAU 36 TO AROUND 115 KTS. THE
INTENSIFICATION TREND WILL THEN HALT AS EASTERLY SHEAR BEGINS TO
INCREASE TO AROUND 25-30 KTS. AN INTENSITY OF 115 KTS IS CURRENTLY
FORECAST FOR THE TIME OF LANDFALL IN LUZON. AFTER MAKING LANDFALL, 
THE MOUNTAINOUS TERRAIN WILL RAPIDLY WEAKEN THE VORTEX. ONCE THE 
SYSTEM ENTERS THE SOUTH CHINA SEA REDEVELOPMENT WILL BE HINDERED BY 
INCREASING SOUTHERLY SHEAR AND DRY AIR INTRUSION. AS A RESULT, 32W IS 
FORECAST TO WEAKEN THROUGH THE REMAINDER OF THE FORECAST PERIOD AS IT 
TRACKS TOWARD SOUTHERN TAIWAN.


MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE CONTINUES TO BE IN
VERY GOOD AGREEMENT THROUGH TAU 72, WITH THE EXCEPTION OF NAVGEM,
WHICH TRACKS THE VORTEX MUCH FURTHER NORTH. DISCOUNTING NAVGEM,
THERE IS A 65 NM CROSS-TRACK SPREAD AT TAU 48 AND A MERE 70 NM
SPREAD AT TAU 72, LENDING HIGH CONFIDENCE IN THE JTWC TRACK
FORECAST THROUGH TAU 72. AFTER TAU 72, MODELS BEGIN TO DIVERGE WITH
VARYING SHARPNESS OF THE NORTHWARD TURN. GFS HAS THE WIDEST TURN
WHILE GALWEM HAS THE SHARPEST. SPREAD AT TAU 120 IS MUCH SMALLER
COMPARED TO THE PREVIOUS MODEL RUN, AND IS NOW ABOUT 190 NM. THE
JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS
WITH HIGH CONFIDENCE THROUGH TAU 72 AND MEDIUM CONFIDENCE THEREAFTER. 
INTENSITY GUIDANCE AGREES ON RAPID INTENSIFICATION (RI) THROUGH TAU 
36, WITH NEARLY ALL AVAILABLE RI AIDS CONTINUING TO TRIGGER THIS 
MODEL RUN. PEAK INTENSITIES RANGE FROM 100-125 KTS WITH HAFS-A BEING 
THE MOST AGGRESSIVE MODEL. MODELS THEN AGREE ON RAPID WEAKENING 
THROUGH TAU 72 AND MORE GRADUAL WEAKENING THROUGH TAU 120. THE JTWC 
INTENSITY FORECAST IS PLACED CLOSER TO THE HAFS-A DUE TO THE 
EXPECTATION OF RAPID DEVELOPMENT UNDER THE EFFECTS OF THE HIGHLY 
CONDUCIVE ENVIRONMENT. 

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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