WDXS31 PGTW 191500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05S (FINA)        
WARNING NR 006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.5S 132.6E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 206 NM NORTH-NORTHEAST OF DARWIN,
   AUSTRALIA
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 02 KTS
   SIGNIFICANT WAVE HEIGHT: 19 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
UPPER-LEVEL OUTFLOW HAS IMPROVED MARKEDLY OVER THE EASTERN QUADRANT
OF THE SYSTEM OVER THE PAST SIX HOURS, WITH DECREASING PRESSURE
DEPICTED IN BOTH THE ANIMATED RGB WATER VAPOR IMAGERY AND ANIMATED
ENHANCED INFRARED (EIR) SATELLITE IMAGERY. ANIMATED WATER VAPOR
IMAGERY SHOWS EXPANDING EASTWARD OUTFLOW, WITH UPPER-LEVEL OUTFLOW
STRIATIONS ALONG THE EASTERN EDGE OF THE CENTRAL DENSE OVERCAST
(CDO). EIR IMAGERY INDICATES THE PREVIOUSLY TIGHT TEMPERATURE
GRADIENT ALONG THE EASTERN QUADRANT HAS EASED. ADDITIONALLY, THE
CIMSS TC-SCALE ATMOSPHERIC MOTION VECTORS IMAGERY SHOWS THAT THE
NORTHERLY FLOW HAS DEFLECTED SOUTH-SOUTHEASTWARD DUE TO THE
EXPANDING EASTWARD OUTFLOW, WITH THE NARROW CONVERGENT REGION
SHIFTING FURTHER EAST AWAY FROM THE SYSTEM. CONSEQUENTLY, THE SYSTEM 
HAS CONTINUED TO CONSOLIDATE WHILE BECOMING QUASI-STATIONARY. ANIMATED 
RADAR IMAGERY BRIEFLY SHOWED A DEVELOPING EYE AND WELL-DEFINED LOW-
LEVEL CIRCULATION CENTER, WHICH HAS SUBSEQUENTLY WEAKENED OVER THE 
PAST TWO HOURS. ADDITIONALLY, A 191148Z ASCAT-B BULLSEYE IMAGE SHOWED 
A COMPACT CORE WITH NUMEROUS 50-55 KNOT WINDS AND AN ISOLATED 60 KNOT 
WIND. THIS DATA SUPPORTS THE INITIAL INTENSITY ASSESSMENT OF 60 KNOTS 
AND IS IN GOOD AGREEMENT WITH THE SUBJECTIVE AND OBJECTIVE INTENSITY 
ESTIMATES. THE INITIAL POSITION IS BASED ON THE RADAR IMAGERY WITH 
HIGH CONFIDENCE.  

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: COMPETING STEERING INFLUENCE, WITH
NEAR-EQUATORIAL RIDGE (NER) TO THE NORTHEAST AND SUBTROPICAL RIDGE
(STR) BUILDING TO THE SOUTH. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   ADRM: T3.5 - 55 KTS
   CIMSS ADT: 55 KTS AT 191200Z
   CIMSS AIDT: 44 KTS AT 191200Z
   CIMSS D-PRINT: 53 KTS AT 191200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: DESPITE THE BRIEF RESPITE, NORTHERLY VERTICAL 
WIND SHEAR IS FORECAST TO PERSIST AND INCREASE LEADING TO A STEADY 
WEAKENING TREND FROM TAU 12 THROUGH TAU 48. INTERACTION WITH LAND FROM 
TAU 48 TO TAU 96 WILL ALSO AID IN WEAKENING THE SYSTEM AS IT SKIRTS 
THE NORTHERN COAST OF AUSTRALIA. A SLIGHT INTENSIFICATION TO 65 KNOTS 
MAY OCCUR WITHIN THE NEXT 12 HOURS IF THE SYSTEM CAN CONTINUE TO 
COCOON ITSELF FROM THE INCREASING VWS AND DRY AIR ENTRAINMENT. AFTER 
TAU 96, TC 05S WILL TRACK BACK OVER WATER WITH POTENTIAL FOR A SHORT 
PERIOD OF INTENSIFICATION BEFORE IT IS OVERCOME BY EXTENSIVE DRY AIR 
ENTRAINMENT. TC 05S IS FORECAST TO TURN SHARPLY SOUTHWARD OVER THE 
NEXT 24 HOURS AS THE STR TO THE SOUTH BUILDS QUICKLY. AFTER TAU 36, 
THE SYSTEM WILL TURN SOUTHWESTWARD TO WEST-SOUTHWESTWARD AS IT TRACKS 
ALONG THE NORTHERN PERIPHERY OF THE STR THROUGH TAU 120.   

MODEL DISCUSSION: DETERMINISTIC MODELS REMAIN IN FAIR AGREEMENT, WITH 
A 140NM TO 230NM CROSS-TRACK SPREAD FROM TAU 96 TO TAU 120. HOWEVER, 
THE 190600Z GEFS AND EPS RUNS CONTINUE TO SHOW A WIDE SWATH OF 
SOLUTIONS REFLECTING HIGH UNCERTAINTY AND LOW CONFIDENCE IN THE TIMING 
OF THE SHARP POLEWARD AND WESTWARD TRACK TURNS. RELIABLE INTENSITY 
GUIDANCE IS MIXED WITH HAFS-A THE MOST AGGRESSIVE MODEL SHOWING A PEAK 
INTENSITY OF 80 KNOTS NEAR TAU 60. THE BULK OF THE INTENSITY GUIDANCE 
SHOWS A FLATTER INTENSITY TREND THROUGH TAU 60. THE 190600Z HAFS-A RUN 
INITIALLY INDICATES SIGNIFICANT UNREALISTIC TILT IN THE VORTEX AND DRY 
AIR ENTRAINMENT, WITH RAPID VERTICAL ALIGNMENT AND REMOISTENING AFTER 
TAU 48 THAT PRODUCES THE SHARP INTENSIFICATION TO 80 KNOTS BY TAU 60. 
WITH THE HAFS-A TRACK FURTHER NORTH OVER WATER, YOU CAN'T NECESSARILY 
RULE THIS SCENARIO OUT BUT IT DOES APPEAR TO BE A BIT OPTIMISTIC. GFS 
INITIALIZES BETTER SHOWING A VERTICALLY ALIGNED SYSTEM WITH DRY AIR 
ENTRAINMENT STRUGGLING OVER THE NEXT TWO DAYS BEFORE RAPIDLY 
CONSOLIDATING SOUTHWEST OF MELVILLE ISLAND AFTER TAU 72, WITH A PEAK 
INTENSITY OF 78 KNOTS AT TAU 84. DUE TO THE UNCERTAINTY IN THE TRACK 
AND THE DIRECT IMPACT OF THE TRACK FORECAST ON THE INTENSITY FORECAST, 
THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY FORECAST THROUGH TAU 72.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: LOW
   TRACK 72-120 HR: MEDIUM
   INTENSITY 00-72 HR: LOW
   INTENSITY 72-120 HR: MEDIUM//
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