WDPN31 PGTW 052100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (YINXING) WARNING NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.9N 125.0E
   INITIAL INTENSITY: 90 KTS
   GEOGRAPHIC REFERENCE: 304 NM NORTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM
CONTINUED TO SLOWLY COALESCE AND INTENSIFY IN THE PHILIPPINE SEA AS
EVIDENCED BY OUTER BANDS WRAPPING TIGHTER INTO A SYMMETRICAL AND
MORE COMPACT CENTRAL COLD COVER WITH DEEPENING AND OVERSHOOTING
CLOUD TOPS AND A PINHOLE FORMATIVE EYE. ADDITIONALLY, THE EIR LOOP
SHOWS A VIGOROUS POLEWARD OUTFLOW. THE INITIAL POSITION, ADJUSTED FOR 
A SLIGHT FORWARD TILT, IS PLACED WITH HIGH CONFIDENCE BASED ON THE 
FORMATIVE EYE. THE INITIAL INTENSITY IS ALSO PLACED WITH HIGH
CONFIDENCE BASED ON IDENTICAL AND NEARLY CONCENTRIC DVORAK ESTIMATES 
FROM PGTW, RJTD, AND RCTP, AND REFLECTS THE IMPROVED 6-HR WRAP AND EIR 
CONVECTIVE SIGNATURE. ANALYSIS INDICATES A HIGHLY FAVORABLE 
ENVIRONMENT WITH LOW VWS, WARM ALONG-TRACK SSTS, AND ROBUST 
VENTILATION.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO
THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   RJTD: T5.0 - 90 KTS
   RCTP: T5.0 - 90 KTS
   CIMSS SATCON: 82 KTS AT 051408Z
   CIMSS ADT: 59 KTS AT 051420Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 05-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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: TYPHOON YINXING WILL CONTINUE ON ITS CURRENT
NORTHWESTWARD TRACK UP TO TAU 24; AFTERWARD, A SECONDARY STR BUILDING 
IN FROM THE WEST NEAR HAINAN WILL ASSUME STEERING AN DRIVE THE CYCLONE 
ON A MORE WESTWARD TRAJECTORY THROUGH THE LUZON STRAIT AND INTO THE 
SOUTH CHINA SEA (SCS). THE HIGHLY FAVORABLE ENVIRONMENT WILL PROMOTE 
INTENSIFICATION TO A PEAK OF 105KTS BY TAU 24, FUELED BY INCREASED 
POLEWARD OUTFLOW AS THE SYSTEM GETS CLOSER TO THE SOUTHWESTERLY JETS 
AHEAD OF A TRANSITING MID-LATITUDE TROUGH. AFTERWARD, THE RELATIVE VWS 
WILL INCREASE, SST AND OHC VALUES DECREASE IN THE WAKE OF A PREVIOUS 
CYCLONE (23W), INTERACTION WITH LUZON, THEN THE DRIFT INTO A COLD 
NORTHEASTERLY SURGE IN THE SCS WILL SLOWLY THEN RAPIDLY ERODE THE 
SYSTEM DOWN TO 45KTS BY TAU 120. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY TIGHT AGREEMENT WITH
AN EVEN ACROSS SPREAD TO A MERE 92NM BY TAU 72; AFTERWARD, THE MODELS 
SPREAD OUT TO 360NM AT TAU 120 WITH NVGM THE NOTABLE RIGHT-OF-TRACK 
AND ERRATIC OUTLIER, LENDING HIGH CONFIDENCE UP TO TAU 72, THEN LOW 
CONFIDENCE AFTERWARD, TO THE JTWC TRACK FORECAST. THERE IS MEDIUM 
CONFIDENCE TO THE INTENSITY FORECAST UP TO TAU 72, THEN LOW CONFIDENCE 
AFTERWARD. 

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
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