WDPN31 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (YINXING) WARNING NR 013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.0N 124.4E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 283 NM NORTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: WESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 34 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAGGED EYE
FEATURE THAT HAS DEVELOPED OVER THE LAST SIX HOURS SURROUNDED BY
DEEP CONVECTION WHICH CONTINUES TO OVERCOME INFLUENCE FROM MODERATE
SOUTHWESTERLY VERTICAL WIND SHEAR (VWS). WATER VAPOR IMAGERY
EXHIBITS STRONG POLEWARD OUTFLOW ENHANCED BY THE JET TO THE NORTH.
THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE
AFOREMENTIONED ANIMATED MSI DEPICTING THE NEWLY DEVELOPED EYE
FEATURE. THE INITIAL INTENSITY OF 100 KTS IS ASSESSED WITH HIGH
CONFIDENCE BASED ON THE AFOREMENTIONED EYE THAT HAS EMERGED OVER
THE LAST SIX HOURS, INDICATING FURTHER INTENSIFICATION, WHILE 
ACCOMPANIED BY THE AGENCY AND OBJECTIVE FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE NORTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   RJTD: T5.0 - 90 KTS
   RCTP: T5.5 - 102 KTS
   KNES: T5.5 - 102 KTS
   CIMSS SATCON: 89 KTS AT 060242Z
   CIMSS ADT: 74 KTS AT 060530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

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: TYPHOON (TY) YINGXING WILL TRACK WESTWARD UNDER 
THE STEERING INFLUENCE OF THE STR TO THE NORTH IN THE NEAR-TERM, WITH
ANOTHER DEEP-LAYER RIDGE FOLLOWING CLOSELY BEHIND TO CONTINUE THE 
WESTWARD TRACK. AS THE SYSTEM WEAKENS TOWARDS THE END OF THE FORECAST 
PERIOD, THE STEERING FLOW ON THE MID- AND LOW-LEVELS WILL CAUSE THE 
SYSTEM TO TRACK SOUTHWESTWARD AFTER TAU 96 WITH NORTHEASTERLY FLOW IN 
THE SOUTH CHINA SEA. AS THE SYSTEM NEARS NORTHERN LUZON OVER THE NEXT 
24 HOURS, RATE OF INTENSIFICATION WILL BE MITIGATED BY MODERATE TO 
HIGH VERTICAL WIND SHEAR AND UPWELLING SEAS INTRODUCING COOL SEA 
SURFACE TEMPERATURES. AFTER PEAKING AT 105KTS BY TAU 24, VERTICAL WIND 
SHEAR WILL INCREASE SIGNIFICANTLY AND INITIATE THE WEAKENING TREND AS 
THE SYSTEM TRANSITS INTO THE SOUTH CHINA SEA. HIGH VERTICAL WIND SHEAR
ASSOCIATED WITH A COLD SURGE EVENT INITIATING FROM THE TAIWAN
STRAIT THROUGH THE SOUTH CHINA SEA WILL CONTINUE TO GRADUALLY ERODE
THE SYSTEM UNTIL IT WEAKENS TO 45KTS BY THE END OF THE FORECAST
PERIOD. 

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN STRONG
AGREEMENT THAT THE SYSTEM WILL TRACK OVERALL WESTWARD THROUGH THE
REMAINDER OF THE FORECAST PERIOD. THE JTWC MULTI-MODEL INTENSITY
GUIDANCE REPRESENTS A LARGER SPREAD OF SOLUTIONS. ON THE UPPER END,
THE HAFS-A SOLUTION PEAKS AT 120KTS AT TAU 72. ON THE OTHER HAND,
GFS REPRESENTS RAPID AND CONSISTENT WEAKENING STARTING AT TAU 0.
THE JTWC INTENSITY FORECAST LIES CLOSELY TO THE CONSENSUS IN THE
NEAR-TERM FORECAST BUT DECREASES SLIGHTLY FASTER THAN CONSENSUS AT
THE END OF THE FORECAST PERIOD.

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