WDXS31 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02S (BHEKI) WARNING NR 
017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.0S 54.4E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 103 NM SOUTH-SOUTHWEST OF ST DENIS
   MOVEMENT PAST 6 HOURS: WESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A FULLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) SOUTHWEST OF LA
REUNION. A 220214Z WSF-M COLOR ENHANCED 89GHZ MICROWAVE IMAGE
SHOWED WELL-DEFINED LOW-LEVEL BANDS WRAPPING INTO A DEFINED LLCC,
WITH THE ONLY SIGNIFICANT CONVECTION AT THAT TIME BEING LIMITED TO
THE DISTANT SOUTHEASTERN QUADRANT. OVERNIGHT, CONVECTION HAD
EXPLODED AND EXPANDED IN AREAL EXTENT, DRIVING A REGENERATION IN
WARNINGS. HOWEVER, OVER THE PAST 12 HOURS, THAT CONVECTION HAS
COLLAPSED, A NOW THE MSI DEPICTS ONLY MODEST CONVECTION DEVELOPING
ALONG THE LOW-LEVEL CONVERGENCE LINES TO THE SOUTH OF THE LLCC.
CIMSS UPPER-LEVEL ANALYSIS, AND MODEL FIELD REVIEW, REVEAL A HIGHLY
UNFAVORABLE ENVIRONMENT. THE SYSTEM IS FULLY EMBEDDED UNDER 45-55
KNOT WESTERLY FLOW ALOFT, SSTS ARE HOVERING NEAR 26C AND DRY AIR
COMPLETELY ENGULFS THE LLCC ABOVE 700MB. HOWEVER, THE SYSTEM LIES
AT THE ENTRANCE REGION OF A JET MAXIMUM AT 200MB, WHICH IS
PROVIDING SOME BAROCLINIC FORCING, AND ALLOWING FOR THE CONSISTENT
BURSTS OF CONVECTION, WHICH IS KEEPING THE INTENSITY UP. THE
INITIAL POSITION AND INTENSITY ARE ASSESSED WITH HIGH CONFIDENCE
BASED ON THE EXPOSED LLCC AND AN EARLIER SCATTEROMETER PASS SHOWING
35-40 KNOT WINDS IN THE SOUTHERN HEMISPHERE OF THE SYSTEM.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: LOW-LEVEL FLOW ON THE NORTHWESTERN SIDE
OF THE MASCARENE HIGH, MODIFIED BY THE PROXIMITY TO LA REUNION. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   CIMSS SATCON: 34 KTS AT 22530Z
   CIMSS ADT: 27 KTS AT 220600Z
   CIMSS AIDT: 39 KTS AT 220600Z
   CIMSS D-MINT: 31 KTS AT 220225Z
   CIMSS D-PRINT: 28 KTS AT 220530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 45-50 KTS
   SST: 25-26 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: DRY MID-LEVEL AIR ENGULFING THE SYSTEM. 

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 02S CLEARLY HAS DEVELOPED FEATURES
ASSOCIATED WITH A SUBTROPICAL CYCLONE BUT RETAINS OTHER FEATURES
MORE TROPICAL IN NATURE. THE SYSTEM REMAINS WARM CORE, BUT THE
DEPTH OF THE WARM CORE IS LIMITED TO BELOW 700MB. SSTS REMAIN
BORDERLINE AT 26C AND THE SYSTEM IS MOVING UNDER JET-LEVEL
WESTERLIES ALOFT. ALL IN ALL, THE CURRENT ASSESSMENT IS THAT THE
SYSTEM IS PREDOMINANTLY TROPICAL IN NATURE, WITH SOME HYBRID
ASPECTS. AFTER HAVING SLOWED DOWN AND STALLED SOUTHWEST OF LA
REUNION, DUE TO TERRAIN INFLUENCES ON THE LOW-LEVEL STEERING FLOW,
THE SYSTEM HAS ALREADY STARTED TO MOVE TOWARDS THE SOUTHWEST BASED
ON THE LATEST MSI LOOP. THE FURTHER AWAY IT GETS FROM LA REUNION,
THE MORE IT WILL ACCELERATE TOWARDS THE SOUTHWEST, ALONG THE
WESTERN SIDE OF THE MASCARENE HIGH. THE LATEST IMAGERY ALSO SHOWS
WHAT COULD BE THE START OF ANOTHER ROUND OF CONVECTIVE ACTIVITY HAS
STARTED TO DEVELOP TO THE SOUTHEAST OF THE CENTER, SIMILAR TO 24
HOURS AGO. THE SYSTEM STILL SITS NEAR THE ENTRANCE REGION OF A
200MB JET MAX, WHICH COULD STILL PROVIDE ENOUGH BAROCLINIC ENERGY
TO SUPPORT CONVECTIVE DEVELOPMENT. THE MESOSCALE MODELS ALSO SHOW
THIS AND INDICATE THE SYSTEM WILL LIKELY MAINTAIN 35 KNOT
INTENSITY, OR EVEN SLIGHTLY INTENSIFY, OVER THE NEXT 12 HOURS. BUT
AFTER THAT, THE JET MAX MOVES AWAY TO THE EAST, AND THE SYSTEM
MOVES UNDER EVEN DRIER MID-LEVEL AIR. TC 02S WILL WEAKEN BELOW 35
KNOTS BY TAU 24 UNDER THESE HIGHLY UNFAVORABLE CONDITIONS. 

MODEL DISCUSSION: ALL AVAILABLE TRACK GUIDANCE IS IN AGREEANCE THAT
TC 02S WILL START TO MOVE TOWARDS THE SOUTHWEST IMMINENTLY AND
CONTINUE ON THAT COURSE THROUGH THE SHORT DURATION OF THE FORECAST
PERIOD. INTENSITY GUIDANCE IS MIXED, WITH THE HWRF SHOWING THE
SYSTEM INTENSIFYING UP TO 45 KNOTS IN THE NEXT 6 TO 12 HOURS BEFORE
WEAKENING THEREAFTER, WHILE THE HAFS-A IS FLAT FOR 12 HOURS THEN
RAPIDLY WEAKENS THROUGH BEYOND THAT. THE JTWC FORECAST CLOSELY
FOLLOWS THE HAFS-A THROUGH THE FORECAST PERIOD. 

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