WDXS31 PGTW 160300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05S (BELAL)
WARNING NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.1S 57.8E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 123 NM SOUTH-SOUTHEAST OF PORT LOUIS,
MAURITIU
   MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
CYCLONE (TC) 05S (BELAL) CONTINUING TO TRACK SOUTHEASTWARD AT 9KTS
OVER THE PAST 12 HOURS. DRY AIR ENTRAINMENT ALONG THE WESTERN
PERIPHERY IS EVIDENT ON ANIMATED WATER VAPOR SATELLITE
IMAGERY, SHOWING A MOSTLY CLOUD-FREE AREA BEING ENHANCED BY THE
PROMINENT DEEP-LAYER WESTERLIES THE SYSTEM HAS BEGUN TO ENCOUNTER.
IN SUCH, OUTFLOW ALOFT HAS SHIFTED TO PREDOMINANTLY EASTWARD AND
HAS CAUSED THE VORTEX TO DEVELOP AN EASTWARD TILT WITH HEIGHT. THE
MOSTLY OBSCURED LOW-LEVEL CIRCULATION CENTER HAS GRADUALLY EMERGED
IN THE NORTHWESTERN QUADRANT OF THE SYSTEM DUE TO THE INFLUENCE OF
STRONG (25-30KTS) VERTICAL WIND SHEAR. THE INITIAL POSITION IS
PLACED WITH MEDIUM CONFIDENCE BASED ON A 152315Z SSMIS 37GHZ
SATELLITE MICROWAVE IMAGE. THE INITIAL INTENSITY OF 65 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE SUBJECTIVE AND
OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: DEEP-LAYERED STEERING RIDGE ENTRENCHED
TO THE NORTH WITH AN EXTENSION OF THE RIDGE TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   KNES: T4.5 - 77 KTS
   FMEE: T4.5 - 77 KTS
   CIMSS ADT: 53 KTS AT 152330Z
   CIMSS AIDT: 50 KTS AT 152330Z
   CIMSS DPRINT: 54KTS AT 160000Z
   

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 30+ KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE EASTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: TC 05S (BELAL) IS FORECAST TO TRACK
EAST-SOUTHEASTWARD TO EASTWARD THROUGH TAU 48. THEREAFTER, THE
SYSTEM IS LIKELY TO BE REDIRECTED BY RIDGING TO THE NORTH AND EAST, 
STEERING THE SYSTEM ONTO A NEAR RECIPROCAL TRACK HEADING THROUGH TAU
60.  OVER THIS PERIOD, THE STRONG (20-30 KTS) VERTICAL WIND SHEAR
AND DRY AIR ARE EXPECTED TO GRADUALLY LOWER SYSTEM INTENSITY.  AS
THE SYSTEM CHECKMARKS BACK TO A NEAR RECIPROCAL HEADING NEAR TAU 60
IT WILL THEN MAKE A GRADUAL TURN POLEWARD THROUGH TAU 120,
SUBJECTING THE SYSTEM TO COLDER SEA SURFACE TEMPERATURES (26 TO 27
C) AND, ULTIMATELY, STEADILY DECAY AND WEAKEN THE TC AS IT EMBEDS 
FURTHER INTO DEEP WESTERLIES.

MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE IS IN EXCEPTIONAL
AGREEMENT THROUGH TAU 60, SUGGESTING TC 05S (BELAL) WILL TRACK
EASTWARD AT 9-10 KTS THROUGH TAU 48 AND THEN ABRUPTLY BEGIN TO
STALL OUT TRACK SPEED FROM TAU 48 TO TAU 60. NEARLY ALL JTWC MODEL
CONSENSUS MEMBERS, EXCEPT NAVGEM, SHOW THE SYSTEM CHECK MARKING BACK 
ON A NEAR RECIPROCAL TRACK HEADING NEAR TAU 60. FROM TAU 72 FORWARD, 
A MYRIAD OF TRACK SOLUTIONS ARE OFFERED, ALL WITH A SOUTHWARD 
COMPONENT. ECMWF IS THE FURTHEST WEST OF THE MEMBERS, TRACKING THE 
SYSTEM WEST-SOUTHWEST THROUGH TAU 120, AND UKMET IS THE FURTHEST 
EAST, TRACKING THE SYSTEM SOUTHEAST THROUGH TAU 120. INTENSITY 
GUIDANCE SUGGESTS A GRADUAL DECAY IN INTENSITY IS LIKELY TO OCCUR 
THROUGH TAU 60, AND THEN STEADILY DROP AS THE TRACK CHECKMARKS AND 
TRACKS POLEWARD THROUGH TAU 120.

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