TC AMBALI(03S): rapid intensification



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WARNING POSITION:
   051200Z --- NEAR 9.2S 62.7E
     MOVEMENT PAST SIX HOURS - 220 DEGREES AT 08 KTS
     POSITION ACCURATE TO WITHIN 020 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT
                            015 NM SOUTHEAST QUADRANT
                            010 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
REMARKS:
051500Z POSITION NEAR 9.4S 62.6E.
05DEC19. TROPICAL CYCLONE 03S (AMBALI), LOCATED APPROXIMATELY 595
NM WEST-SOUTHWEST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT
08 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON
RECENT SATELLITE FIXES FROM PGTW, KNES AND FMEE AND 050921Z GMI
SENSOR MICROWAVE SATELLITE IMAGES WHICH SHOW TIGHT CONVECTIVE BANDING
AND A DEVELOPING EYE. THE INTENSITY OF 70 KNOTS IS SET BETWEEN LOW
END SUBJECTIVE DVORAK ESTIMATES OF T3.5 (55 KNOTS) FROM KNES, FMEE
AND FIMP AND A HIGH END ESTIMATE OF T4.5 (77 KNOTS) FROM PGTW. TC 03S
IS RAPIDLY INTENSIFYING UNDER THE INFLUENCE OF LOW VERTICAL WIND
SHEAR (5-10 KNOTS), A VERY WARM SEA SURFACE (29-30C) AND A STRONG
POLEWARD OUTFLOW CHANNEL TO THE SOUTHEAST. THE CYCLONE IS TRACKING
SOUTHWESTWARD ALONG THE WESTERN PERIPHERY OF A DEEP-LAYER STEERING
RIDGE TO THE EAST. OVER THE NEXT 48 HOURS, TC 03S WILL CONTINUE
TRACKING GENERALLY SOUTH-SOUTHWESTWARD FOLLOWING THE FLOW ASSOCIATED
WITH THE CURRENT STEERING RIDGE. AS THE SYSTEM SHALLOWS LATER IN THE
FORECAST PERIOD, IT WILL LIKELY TURN A BIT WESTWARD FOLLOWING THE
LOW- TO MID-LEVEL FLOW. NEAR-TERM FORECAST INTENSITIES ARE
SIGNIFICANTLY HIGHER ON THE CURRENT FORECAST THAN THE PREVIOUS
FORECAST BASED ON EXPECTATIONS THAT THE OBSERVED RAPID
INTENSIFICATION TREND WILL CONTINUE FOR THE NEXT SIX TO TWELVE HOURS.
THE CURRENT FORECAST CALLS FOR A PEAK INTENSITY OF 100 KNOTS IN
TWELVE HOURS, BUT THE EXACT VALUE AND TIMING ARE UNCERTAIN. AFTER TAU
24, UPPER-LEVEL CONDITIONS WILL BECOME LESS FAVORABLE, PARTICULARLY
THE OUTFLOW PATTERN, HALTING THE INTENSIFICATION TREND FOR THE
COMPACT SYSTEM. SLOW TO STEADY WEAKENING BETWEEN TAU 36 AND
DISSIPATION AROUND TAU 96 IS ANTICIPATED AS INCREASING VERTICAL WIND
SHEAR AND LESS FAVORABLE OUTFLOW IMPACT THE SYSTEM. NUMERICAL MODELS
ARE IN GOOD AGREEMENT THROUGH TAU 36, BUT DIVERGE THEREAFTER DUE TO
DIFFERENCES IN THEIR PREDICTIONS OF STORM INTENSITY AND RESULTANT
STEERING LEVEL. THIS NOTED MODEL SPREAD LENDS LOW CONFIDENCE TO THE
CURRENT JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
051200Z IS 24 FEET. NEXT WARNINGS AT 060300Z AND 061500Z. REFER TO
TROPICAL CYCLONE 02S (TWO) WARNINGS (WTXS31 PGTW) FOR TWELVE-HOURLY
UPDATES.//
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CURRENT INTENSITY: 70KTS . FORECAST PEAK INTENSITY: 100KTS IN 12H


Rédigé par PATRICK HOAREAU le Jeudi 5 Décembre 2019 à 19:22