WDXS31 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 08S (BATSIRAI) 
WARNING NR 013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.1S 58.3E
   INITIAL INTENSITY: 120 KTS
   GEOGRAPHIC REFERENCE: 133 NM NORTH-NORTHEAST OF PORT LOUIS,
MAURITIUS
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 45 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAPIDLY
INTENSIFYING SYSTEM, HAVING DEVELOPED A 15NM EYE OVER THE PREVIOUS
SIX TO TWELVE HOURS. A SERIES OF MICROWAVE IMAGERY BETWEEN A
012140Z AMSR AND A 020036Z SSMIS SHOW THE COMPACT CORE OF DEEP
CONVECTION SURROUNDED BY A RAPIDLY DEVELOPING OUTER EYEWALL,
INDICATIVE OF A LIKELY NEAR-TERM EYEWALL REPLACEMENT CYCLE (ERC).
THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE
020036Z SSMIS 37GHZ MICROWAVE IMAGE, THE 15NM EYE FEATURE IN MET-8
EIR AND ANIMATED RADAR DATA FROM MAURITIUS, WHICH SHOWS THE EYE TO
GOOD EFFECT. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM
CONFIDENCE AT A HEFTY 120 KNOTS, SLIGHTLY ABOVE THE FMEE AND FIMP
T6.0 ESTIMATES AND HEDGED TOWARDS THE PGTW T6.5. OBJECTIVE ADT AND
SATCON ESTIMATES ARE UNREASONABLY LOW, IN THE CASE OF THE ADT DUE
TO CONSTRAINTS, THOUGH THE RAW ADT IS AT T6.5 AT 020000Z. THE
SYSTEM IS MOVING IN A TROCHODIAL FASHION WITH THE AVERAGE MOTION
VECTOR TOWARDS THE SOUTHWEST. ANALYSIS REVEALS AN OVERALL FAVORABLE
ENVIRONMENT WITH LOW TO MODERATE VWS, WARM (28C) SSTS AND STRONG
RADIAL OUTFLOW WITH AN ENHANCED OUTFLOW CHANNEL TO THE NORTH.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: NORTHERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE SOUTH. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.5 - 127 KTS
   FMEE: T6.0 - 115 KTS
   FIMP: T6.0 - 115 KTS
   CIMSS SATCON: 74 KTS AT 012038Z
   CIMSS ADT: 90 KTS AT 020015Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG RADIAL
   OTHER FACTORS: NEAR-TERM EYEWALL REPLACEMENT CYCLE (ERC)

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   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 08S IS FORECAST TO CONTINUE TRACKING
WEST-SOUTHWESTWARD OVER THE NEXT 24 TO 36 HOURS ALONG AN EXTENSION
OF THE STR CENTERED TO THE SOUTHWEST. BY TAU 36 THE STR WILL
QUICKLY MOVE TO THE EAST AND SLIDE INTO A POSITION DUE SOUTH OF THE
SYSTEM AND TC 08S WILL SLOW DOWN AND SHIFT TO A WESTWARD TRACK
DURING THIS TIME. AFTER TAU 48 AND DEEP, MID-LATITUDE TROUGH WILL
ERODE THE STEERING RIDGE FROM THE WEST, AND TC 08S WILL TURN ONTO A
MORE SOUTHWESTWARD TRACK ONCE MORE AS IT APPROACHES THE CENTRAL
COAST OF MADAGASCAR. THE SYSTEM IS EXPECTED TO MAKE LANDFALL AFTER
TAU 72, AND QUICKLY CROSS THE ISLAND, AND REEMERGE INTO THE
MOZAMBIQUE CHANNEL BY TAU 120. ANALYSIS OF RECENT MICROWAVE IMAGERY
SUGGESTS ERC HAS ALREADY BEGUN OR IS IMMINENT. THE SYSTEM HAS THUS
LIKELY REACHED ITS PEAK INTENSITY AND ONCE ERC BEGINS, WILL WEAKEN
BY AT LEAST 15 KNOTS IF NOT A BIT MORE. NO MAJOR CHANGES IN THE
SYNOPTIC ENVIRONMENT ARE ANTICIPATED AND AFTER THE ERC COMPLETES
WITHIN 12 TO 18 HOURS, RE-INTENSIFICATION IS EXPECTED, TO A SECOND
PEAK OF 125 KNOTS PRIOR TO LANDFALL. THE SYSTEM WILL DRAMATICALLY
WEAKEN AS IT CROSSES OVER THE RUGGED TERRAIN 2000 METER HEIGHTS OF
CENTRAL MADAGASCAR, AND IS EXPECTED TO EMERGE INTO THE MOZAMBIQUE
CHANNEL AS A 60 KNOT CYCLONE. 

MODEL DISCUSSION: DETERMINISTIC AND ENSEMBLE GUIDANCE, WITH THE
EXCEPTION OF THE NAVGEM TRACKER, ARE IN GOOD AGREEMENT THROUGH THE
DURATION OF THE FORECAST PERIOD. THE JTWC TRACK REMAINS CONSISTENT
WITH THE PREVIOUS FORECAST, AND LIES ROUGHLY ALONG THE NORTHERN
SIDE OF THE GUIDANCE PACKAGE, NEAR THE CONSENSUS MEAN WITH HIGH
CONFIDENCE. WITH THE EXCEPTION OF THE DECAY SHIPS, ALL OTHER
INTENSITY MEMBERS, IN PARTICULAR THE HWRF AND COAMPS-TC MESOSCALE
MODELS, SUGGEST VARYING DEGREES OF NEAR-TERM WEAKENING IN RESPONSE
TO THE LIKELY ERC, FOLLOWED BY RENEWED INTENSIFICATION. THE JTWC
FORECAST TRACKS THE HWRF CLOSELY THROUGH TAU 36, THEN GOES ABOUT 10
KNOTS HIGHER THAN THE HIGHEST GUIDANCE THROUGH LANDFALL AND THEN
ONCE AGAIN TRACKS THE HWRF AFTER TAU 96. CONFIDENCE IS LOW TO
MEDIUM IN THE INTENSITY FORECAST DUE TO THE UNCERTAINTY SURROUNDING
THE TIMING OF ERC AND THE AMOUNT OF THE RESULTING WEAKENING. 

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