WDXS31 PGTW 171500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05S (BELAL) WARNING NR 
011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.


SUMMARY:
   INITIAL POSITION: 24.2S 63.6E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 511 NM EAST-SOUTHEAST OF ST DENIS
   MOVEMENT PAST 6 HOURS: EASTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET


SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TC 05S
(BELAL) WITH A MINIMALLY OBSTRUCTED VIEW OF THE LOW-LEVEL
CIRCULATION CENTER (LLCC) AND A DISLOCATED UPPER-LEVEL OUTFLOW TO
THE SOUTHEAST OF THE STORM. THE STORM CONTINUES TO CREEP EASTWARD
AS IT BEGINS TO INTERACT WITH A RIDGE TO THE NORTHEAST. THE INITIAL
POSITION WAS IDENTIFIED WITH HIGH CONFIDENCE BY A 171132Z 37GHZ
MICROWAVE PASS REVEALING AN ASYMMETRIC SYSTEM WITH AN EYE-LIKE
STRUCTURE AND THE DEEP CONVECTION TO THE SOUTHWEST WHICH WAS
FURTHER SUPPORTED BY MSI REPRESENTING BANDS OF DEEP CONVECTION
WRAPPING INTO THE LLCC. THE INITIAL INTENSITY WAS ASSESSED WITH LOW
CONFIDENCE BASED ON PERSISTENCE AND THE SUBJECTIVE AND OBJECTIVE
FIXES LISTED BELOW. POWERFUL WEST-NORTHWESTERLY WIND SHEAR
(25-30KTS) ALONG WITH DRY AIR ENTRAINING INTO THE SYSTEM FROM THE
WEST WILL CONTINUE TO FORCE THE STORM TO LOSE STEAM THROUGH THE
REMAINDER OF THE FORECAST PERIOD (TAU 48) DESPITE FAVORABLE SEA
SURFACE TEMPERATURES (SST) OF 26-27C.


INITIAL WIND RADII BASIS: PERSISTENCE


CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A DEEP-LAYER
NEAR-EQUATORIAL RIDGE (NER) TO THE NORTH.


AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   DEMS: T3.0 - 45 KTS
   FMEE: T3.5 - 55 KTS
   CIMSS ADT: 35 KTS AT 170900Z


FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 25-30 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: WEAK POLEWARD


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


3. FORECAST REASONING.


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

FORECAST DISCUSSION: TC 05S (BELAL) IS ANTICIPATED TO CONTINUE TO
CREEP EASTWARD ALONG THE SOUTHERN SIDE OF THE NER TO THE NORTH FOR
THE NEXT 12 HOURS, BUT THEN COMES TO A STOP AND BECOMES
QUASI-STATIONARY AS IT RUNS INTO A BUILDING RIDGE TO THE EAST.
FOLLOWING TAU 24, AS THE SYSTEM RAPIDLY WEAKENS, THE STEERING LEVEL 
PROGRESSIVELY LOWERS, RESULTING IN A SHARP TURN BACK TO THE WEST THEN 
SOUTHWEST, ALONG THE NORTHERN SIDE A LOW- TO MID-LEVEL MID-LATITUDE 
ANTICYCLONE CENTERED TO THE SOUTH. THROUGH THE FORECAST PERIOD, THE 
STORM WILL CONTINUE TO LOSE INTENSITY AS STRONG WIND SHEAR FROM THE 
EAST (25-30KTS) WILL TEAR APART THE VORTEX STRUCTURE, LIMITING THE 
SYSTEM'S CAPABILITY TO REINTENSIFY. TC 05S WILL BE FURTHER WEAKENED BY 
DRY AIR MOVING IN FROM THE WEST, WHICH WILL FULLY ENGULF THE REMNANT 
CIRCULATION. ULTIMATELY THE COMBINATION OF DRY AIR AND PERSISTENT 
SHEAR WILL LEAD TO DISSIPATION BY TAU 48.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN AGREEMENT THAT
TC 05S (BELAL) WILL CONTINUE TO SLOW IN ITS TRANSIT EAST AND NEARLY
COME TO A STOP BY TAU 12. THE MODELS BEGIN TO DIFFER 180 DEGREES IN
DETERMINING WHETHER OR NOT THE STORM WILL TAKE A NORTHERLY OR
SOUTHERLY ROUTE BY TAU 24, WITH A 90 NM CROSS-TRACK SPREAD BOUNDED
BY COAMPS-TC TO THE SOUTH AND GALWEM TO THE NORTH. DESPITE THE
UNCERTAINTY IN WHICH POLE THE STORM WILL VEER, THE MODELS DO
GENERALLY AGREE THAT THE STORM WILL RECURVE TO THE SOUTHWEST AFTER
TAU 36. THE CROSS-TRACK SPREAD CONTINUES TO THE SOUTHWEST, OPENING
TO 212 NM BY THE END OF THE FORECAST PERIOD (TAU 48). ALL JTWC
CONSENSUS MEMBERS AGREE THAT THE SYSTEM WILL RAPIDLY WEAKEN
FOLLOWING TAU 12 THROUGH THE END OF THE FORECAST PERIOD (TAU 48).


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