WDXS31 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05S (FINA)        
WARNING NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.7S 132.6E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 196 NM NORTH-NORTHEAST OF DARWIN,
   AUSTRALIA
   MOVEMENT PAST 6 HOURS: EASTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL CYCLONE (TC) 05S HAS SLOWLY CONSOLIDATED DESPITE A SLOWLY
DEGRADING UPPER-LEVEL ENVIRONMENT OVER THE EASTERN SEMI-CIRCLE. THE
CIMSS TC-SCALE ATMOSPHERIC MOTION VECTORS IMAGERY AND ANIMATED
WATER VAPOR IMAGERY INDICATE A NARROW REGION OF CONVERGENT FLOW AND
STRENGTHENING NORTHERLY UPPER-LEVEL WINDS PRESSING AGAINST THE
EASTERN EDGE OF THE CORE CONVECTION. ADDITIONALLY, DRY AIR ASSOCIATED 
WITH THIS UPPER-LEVEL CONVERGENCE IS BEGINNING TO ENTRAIN INTO THE 
EASTERN SEMI-CIRCLE HINDERING CONVECTIVE DEVELOPMENT AND DECAYING 
EXISTING CONVECTION. HOWEVER, ROBUST POLEWARD AND EQUATORWARD OUTFLOW, 
WARM SST AND LOW TO MODERATE NORTHEASTERLY VERTICAL WIND SHEAR HAVE 
MAINTAINED A SOMEWHAT RAGGED, OBLONG CENTRAL DENSE OVERCAST FEATURE 
OVER THE LOW-LEVEL CIRCULATION CENTER (LLCC). ANIMATED RADAR IMAGERY 
DEPICTS IMPROVED CONVECTIVE BANDING WRAPPING INTO A DEFINED LLCC. A 
190606Z GMI 37GHZ MICROWAVE IMAGE REVEALS A COMPACT CORE WITH A WELL-
DEFINED MICROWAVE EYE FEATURE, WHICH SUPPORTS THE MODEST INCREASE IN 
THE INITIAL INTENSITY FROM 50 TO 55 KNOTS OVER THE PAST SIX HOURS AND
THE INITIAL POSITION WITH HIGH CONFIDENCE. SUBJECTIVE DVORAK ESTIMATES 
OF T3.5 (55 KNOTS) FROM BOTH PGTW AND ADRM ALSO SUPPORT THE INITIAL 
INTENSITY ASSESSMENT WITH MEDIUM CONFIDENCE. CIMSS OBJECTIVE ESTIMATES 
RANGE FROM 39 TO 56 KNOTS.

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: T3.5 - 55 KTS
   ADRM: T3.5 - 55 KTS
   CIMSS SATCON: 56 KTS AT 190600Z
   CIMSS ADT: 49 KTS AT 190530Z
   CIMSS AIDT: 39 KTS AT 190530Z
   CIMSS D-MINT: 50 KTS AT 190446Z
   CIMSS D-PRINT: 50 KTS AT 190600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD
   OTHER FACTORS: WEAK DRY AIR ENTRAINMENT ALONG THE NORTHEASTERN
   FLANK

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: AS FORECAST WELL BY GFS AND HAFS-A, INCREASING
NORTHERLY CONVERGENT FLOW AND VERTICAL WIND SHEAR ARE BEGINNING TO 
IMPACT THE SYSTEM. THUS FAR, TC 05S HAS BEEN ABLE TO MAINTAIN A COMPACT 
CORE WITH STEADY INTENSIFICATION AND IS FORECAST TO INTENSIFY SLIGHTLY 
OVER THE NEXT 12 TO 24 HOURS, WITH A PEAK INTENSITY OF ABOUT 60-65 
KNOTS EXPECTED. GFS SUGGESTS FAVORABLE CONDITIONS SHOULD CONTINUE FOR 
12-18 HOURS WHILE HAFS-A SHOWS INCREASING TILT AND DRY AIR ENTRAINMENT 
WITHIN THE NEXT 6-12 HOURS. THEREFORE, THERE IS SOME UNCERTAINTY IN THE 
PEAK INTENSITY DEPENDING ON HOW WELL THE SYSTEM CAN COCOON ITSELF FROM 
THE INCREASING NORTHERLY FLOW AND VWS. 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. STEADY WEAKENING IS EXPECTED AS THE SYSTEM
APPROACHES NORTHERN AUSTRALIA THEN SKIRTS THE COAST. 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.       

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, THE DETERMINISTIC
MODELS ARE IN FAIR AGREEMENT, WITH A 100NM TO 200NM CROSS-TRACK
SPREAD FROM TAU 96 TO TAU 120. HOWEVER, THE 190000Z 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 78 KNOTS 
NEAR TAU 48 JUST BEFORE LANDFALL. THIS SCENARIO IS POSSIBLE IF THE 
SYSTEM CAN REALIGN VERTICALLY AND REMOISTEN QUICKLY AS HAFS-A SUGGESTS.    

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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