WDPN31 PGTW 112100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 24W (YINXING) WARNING NR 
035//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.9N 109.9E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 114 NM SOUTHEAST OF DA NANG, VIETNAM
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) AND CIRA PROXY VISIBLE SATELLITE
IMAGERY DEPICT A NEARLY FULLY EXPOSED LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH A SMALL FLARE OF DEEP CONVECTION DEVELOPING OVER THE
NORTHWESTERN PERIPHERY. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE EXPOSED CENTER EVIDENT IN PROXY VISIBLE
IMAGERY, WITH ADDITIONAL SUPPORT FROM MULTI-AGENCY POSITION FIXES.
THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON A CONSENSUS OF SUBJECTIVE DVORAK AND AUTOMATED INTENSITY
ESTIMATES AND A PARTIAL 111435Z METOP-C ASCAT PASS SHOWING 30-35
KNOT WINDS EMBEDDED WITHIN THE WESTERN PORTION OF THE LOW-LEVEL
CIRCULATION. TS 24W IS SLOWLY DISSIPATING IN A MARGINALLY UNFAVORABLE 
ENVIRONMENT, WITH UNIDIRECTIONAL (SOUTHERLY) FLOW ALOFT AND ASSOCIATED 
VERTICAL WIND SHEAR AND DRY AIR INTRUSION INTO THE SOUTHERN AND 
EASTERN PERIPHERIES OF THE CIRCULATION.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK AND PARTIAL 111435Z
METOP-C ASCAT PASS

CURRENT STEERING MECHANISM: LOW- TO MID-LEVEL SUBTROPICAL RIDGE
(STR) TO THE NORTHWEST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RCTP: T2.5 - 35 KTS
   DEMS: T2.5 - 35 KTS
   CIMSS ADT: 34 KTS AT 111420Z
   CIMSS AIDT: 34 KTS AT 111420Z
   CIMSS D-PRINT: 45 KTS AT 111530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE POLEWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TROPICAL STORM (TS) 24W WILL CONTINUE TO TRACK
GENERALLY SOUTHWESTWARD ALONG THE PERIPHERY OF THE CURRENT STEERING
RIDGE OVER THE NEXT 24 HOURS. PERSISTENT SOUTHERLY VERTICAL WIND
SHEAR, PASSAGE OVER MARGINALLY WARM WATER, AND DRY AIR INTRUSION
ARE EXPECTED TO RESULT IN GRADUAL WEAKENING OVER THE NEXT SIX
HOURS. THE SYSTEM WILL MAKE LANDFALL IN SOUTHERN VIETNAM BY TAU 12
AND DISSIPATE QUICKLY THEREAFTER.

MODEL DISCUSSION: ASIDE FROM THE MOGREPS-G ENSEMBLE MEAN, A CLEAR
OUTLIER WHICH DEPICTS A SOUTHWARD TO SOUTH-EASTWARD TRACK AND
DISSIPATION OVER WATER ON THE LATEST MODEL RUN, DETERMINISTIC MODEL
GUIDANCE IS IN GOOD AGREEMENT REGARDING THE EXPECTED TRACK AND
INTENSITY FORECAST. THERE IS LITTLE CHANGE TO EITHER IN THE CURRENT
FORECAST, AND CONFIDENCE IS HIGH GIVEN THE STRAIGHTFORWARD STEERING
AND STRUCTURAL INFLUENCES.

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