WDXS31 PGTW 291500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 10S (HAYLEY) WARNING 
NR 006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.7S 120.0E
   INITIAL INTENSITY: 75 KTS
   GEOGRAPHIC REFERENCE: 183 NM NORTHWEST OF BROOME, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TC 10S HAS INTENSIFIED SIGNIFICANTLY OVER THE PAST SIX HOURS.
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS
DEVELOPMENT OF AN 8 NM EYE SURROUNDED BY COOLING DEEP CONVECTIVE
BANDING. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED
ON A 291130Z PGTW SATELLITE EYE FIX AND SSMIS IMAGERY FROM 291046Z.
THE INITIAL INTENSITY OF 75 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON A CONSENSUS OF SUBJECTIVE DVORAK AND AUTOMATED INTENSITY
ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE AND OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE CENTERED TO THE
NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   DEMS: T4.5 - 77 KTS
   APRF: T4.5 - 77 KTS
   CIMSS SATCON: 64 KTS AT 291046Z
   CIMSS ADT: 72 KTS AT 291130Z
   CIMSS AIDT: 64 KTS AT 291130Z
   CIMSS D-MINT: 55 KTS AT 291046Z
   CIMSS D-PRINT: 54 KTS AT 291240Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THE FORECASTED PEAK INTENSITY HAS
INCREASED FROM 75 KNOTS IN THE PREVIOUS WARNING TO 90 KNOTS IN THE
CURRENT WARNING. OTHERWISE, THERE ARE NO SIGNIFICANT CHANGES TO THE
FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TC 10S WILL CONTINUE TO TURN EASTWARD OVER THE
NEXT 12 TO 24 HOURS AS IT FOLLOWS THE PERIPHERAL FLOW ASSOCIATED WITH 
THE NEAR-EQUATORIAL STEERING RIDGE CENTERED TO THE NORTHEAST. THE 
SYSTEM IS EXPECTED TO UNDERGO ADDITIONAL INTENSIFICATION OVER THE 
NEXT 12 HOURS UNDER THE SUPPORTIVE INFLUENCES OF LOW VERTICAL WIND 
SHEAR, VERY WARM SEA SURFACE TEMPERATURES, AND MODERATE POLEWARD 
OUTFLOW. MID-LEVEL VERTICAL WIND SHEAR WILL INCREASE AFTER TAU 12, 
RESULTING IN INTRUSION OF DRY AIR INTO THE SYSTEM AND MARGINAL 
WEAKENING BEFORE THE SYSTEM MAKES LANDFALL OVER THE DAMPIER PENINSULA 
AROUND TAU 24. FOLLOWING LANDFALL, PERSISTENT SHEAR AND LAND 
INTERACTION WILL LEAD TO STEADY DISSIPATION BY TAU 48.

MODEL DISCUSSION: THE MAJORITY OF NUMERICAL TRACK FORECAST
SOLUTIONS CONTINUE TO DEPICT AN EASTWARD TURN FOLLOWED BY LANDFALL
OVER THE DAMPIER PENINSULA AROUND TAU 24. SPREAD INCREASES IN BOTH
THE CROSS-TRACK AND ALONG-TRACK DIRECTIONS THEREAFTER,
CORRESPONDING TO EXPECTED CHANGES IN STORM STRUCTURE ACCOMPANYING
RAPID DISSIPATION. INTENSITY FORECAST GUIDANCE SUPPORTS NEAR-TERM
INTENSIFICATION FOLLOWED BY RAPID WEAKENING. THE LATEST
INTERPOLATED HAFS-A RUN PEAKS THE SYSTEM AT 100 KNOTS IN 12 HOURS,
BEFORE THE SYSTEM CONTENDS WITH INCREASING MID-LEVEL VERTICAL WIND
SHEAR AND CONSEQUENT ENTRAINMENT OF DRIER AIR FROM THE SOUTHWEST.
COAMPS-TC DEPICTS ONLY MARGINAL INTENSIFICATION BUT HAS
UNDER PREDICTED THE RECENTLY OBSERVED RAPID INTENSIFICATION TREND FOR
THE PAST FEW MODEL RUNS. COAMPS-TC, HAFS-A, AND GFS SOLUTIONS
CONVERGE DURING THE WEAKENING PHASE, SUPPORTING THE 24 TO 72 HOUR
INTENSITY FORECAST.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   INTENSITY 00-72 HR: MEDIUM//
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