SOUTH INDIAN: 24S(HABANA) is still close to "Super Typhoon/Cyclone" intensity,forecast to weaken more rapidly after 48h, 11/21utc update


24S(HABANA). 11/22UTC. 9H ANIMATION. 24S REMAINS COMPACT AND WELL ORGANIZED. CLOUD-TOPS ARE SLIGHTLY WARMER SINCE 11/1730UTC. 11/2045UTC SATELLITE BULLETIN FROM JTWC HAD DOVRAK AT T6.0/6.5/W0.5/24HRS STT: W0.5/03HRS. CLICK IF NEEDED TO ANIMATE.


24S(HABANA). 11/22UTC. 9H ANIMATION. 24S REMAINS COMPACT AND WELL ORGANIZED. CLOUD-TOPS ARE SLIGHTLY WARMER SINCE 11/1730UTC. 11/2045UTC SATELLITE BULLETIN FROM JTWC HAD DOVRAK AT T6.0/6.5/W0.5/24HRS  STT: W0.5/03HRS.
24S(HABANA). 11/22UTC. 9H ANIMATION. 24S REMAINS COMPACT AND WELL ORGANIZED. CLOUD-TOPS ARE SLIGHTLY WARMER SINCE 11/1730UTC. 11/2045UTC SATELLITE BULLETIN FROM JTWC HAD DOVRAK AT T6.0/6.5/W0.5/24HRS STT: W0.5/03HRS.
2021 MAR 11 2145UTC #SOUTHERNHEMISPHERE
TC #24S #HABANA #SOUTHINDIANOCEAN
WARNING 16/UPDATE
As of 21:00 UTC Mar 11, 2021:
Location: 18.2°S 72.7°E
Maximum Winds( AT 11/18UTC): 125 kt (230km/h)
Gusts: 150 kt ( 280km/h)
Minimum Central Pressure: 937 mb
CATEGORY US: 4
LOCATED AT 11/21UTC APPROXIMATELY 1000KM EAST-NORTHEAST OF  RODRIGUES ISLAND, MAURITIUS, HAS TRACKED WEST-SOUTHWESTWARD AT  13KM/H OVER THE PAST NINE HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS

Cheers,
Patrick Hoareau
M974World
ILES SOEURS
Cyclone Class 4
 Cheers,PH.

Joint Typhoon Warning Center

24S(HANANA). WARNING 16 ISSUED AT 11/21UTC. TC 24S REMAINS IN AN ENVIRONMENT OF LIGHT VERTICAL SHEAR (5 KT) AND WARM  SEA SURFACE TEMPERATURES NEAR 28C, AND IS CURRENTLY LIMITED ONLY BY  AMBIENT DRY AIR THAT IS BEING PERIODICALLY INGESTED INTO THE  CIRCULATION FROM THE WESTERN AND NORTHERN SEMICIRCLES. AS THE  CYCLONE TURNS SOUTHWARD DURING THE NEXT 48 HOURS, A COMBINATION OF  GRADUALLY INCREASING VERTICAL SHEAR, SLIGHTLY COOLER WATER, AND DRY  ENTRAINMENT WILL LIKELY RESULT IN A GRADUAL DECREASE IN INTENSITY.  BEYOND 48 HOURS, THE TRACK FORECAST BECOMES IMPORTANT, AS A  QUASISTATIONARY MOTION IS EXPECTED TO CAUSE OCEANIC COOLING BENEATH  THE CYCLONE. COMBINED WITH A SIMULTANEOUS INCREASE IN VERTICAL SHEAR  TO 30-40 KT, THIS IS EXPECTED TO RESULT IN RAPID WEAKENING BETWEEN  48 AND 72 HOURS, AND STEADY DECAY THEREAFTER THROUGH 120 HOURS.  THERE IS GENERALLY MODERATE CONFIDENCE IN THIS INTENSITY EVOLUTION. REGARDING THE FORECAST TRACK, TC 24S IS CONTINUING TO ROUND THE  NORTHWESTERN PERIPHERY OF A WEAK SUBTROPICAL RIDGE TO THE SOUTHEAST.  AS THIS RIDGE CONTINUES TO SHIFT EASTWARD, THE CYCLONE WILL TURN  SOUTHWARD AFTER 24 HOURS. BY 48 HOURS, 24S WILL BECOME MAROONED IN A  WEAK STEERING ENVIRONMENT, CONSISTING OF WESTERLY FLOW ALOFT AND  EASTERLY FLOW IN THE LOWER TROPOSPHERE AS A SURFACE HIGH BUILDS IN  FROM THE SOUTHWEST. THERE IS GOOD AGREEMENT IN NUMERICAL MODEL  GUIDANCE THAT A NEAR-STALL WILL OCCUR AROUND 48-72 HOURS, WITH THE  EXCEPTION OF NAVGEM AND GALWEM, WHICH MAINTAIN A BRISK SOUTHEASTWARD  TRACK. GIVEN THE EXPECTATION THAT THE VORTEX WILL RAPIDLY DECAY AND  LOSE VERTICAL COHERENCE DURING THIS TIME, THE JTWC TRACK FORECAST  FOLLOWS A BLEND OF HWRF, COAMPS-TC, ECMWF, EPS, GFS, AND GEFS, WHICH  SHOWS A SLOW TURN WESTWARD AFTER 72 HOURS AS THE LOW-LEVEL EASTERLY  FLOW BECOMES THE DOMINANT STEERING MECHANISM FOR THE WEAKENING  CYCLONE. THIS REPRESENTS A SIGNIFICANT SHIFT WEST COMPARED TO THE  PREVIOUS FORECAST, DUE TO A GROWING MODEL CONSENSUS IN THE WESTWARD  TURN.
24S(HANANA). WARNING 16 ISSUED AT 11/21UTC. TC 24S REMAINS IN AN ENVIRONMENT OF LIGHT VERTICAL SHEAR (5 KT) AND WARM SEA SURFACE TEMPERATURES NEAR 28C, AND IS CURRENTLY LIMITED ONLY BY AMBIENT DRY AIR THAT IS BEING PERIODICALLY INGESTED INTO THE CIRCULATION FROM THE WESTERN AND NORTHERN SEMICIRCLES. AS THE CYCLONE TURNS SOUTHWARD DURING THE NEXT 48 HOURS, A COMBINATION OF GRADUALLY INCREASING VERTICAL SHEAR, SLIGHTLY COOLER WATER, AND DRY ENTRAINMENT WILL LIKELY RESULT IN A GRADUAL DECREASE IN INTENSITY. BEYOND 48 HOURS, THE TRACK FORECAST BECOMES IMPORTANT, AS A QUASISTATIONARY MOTION IS EXPECTED TO CAUSE OCEANIC COOLING BENEATH THE CYCLONE. COMBINED WITH A SIMULTANEOUS INCREASE IN VERTICAL SHEAR TO 30-40 KT, THIS IS EXPECTED TO RESULT IN RAPID WEAKENING BETWEEN 48 AND 72 HOURS, AND STEADY DECAY THEREAFTER THROUGH 120 HOURS. THERE IS GENERALLY MODERATE CONFIDENCE IN THIS INTENSITY EVOLUTION. REGARDING THE FORECAST TRACK, TC 24S IS CONTINUING TO ROUND THE NORTHWESTERN PERIPHERY OF A WEAK SUBTROPICAL RIDGE TO THE SOUTHEAST. AS THIS RIDGE CONTINUES TO SHIFT EASTWARD, THE CYCLONE WILL TURN SOUTHWARD AFTER 24 HOURS. BY 48 HOURS, 24S WILL BECOME MAROONED IN A WEAK STEERING ENVIRONMENT, CONSISTING OF WESTERLY FLOW ALOFT AND EASTERLY FLOW IN THE LOWER TROPOSPHERE AS A SURFACE HIGH BUILDS IN FROM THE SOUTHWEST. THERE IS GOOD AGREEMENT IN NUMERICAL MODEL GUIDANCE THAT A NEAR-STALL WILL OCCUR AROUND 48-72 HOURS, WITH THE EXCEPTION OF NAVGEM AND GALWEM, WHICH MAINTAIN A BRISK SOUTHEASTWARD TRACK. GIVEN THE EXPECTATION THAT THE VORTEX WILL RAPIDLY DECAY AND LOSE VERTICAL COHERENCE DURING THIS TIME, THE JTWC TRACK FORECAST FOLLOWS A BLEND OF HWRF, COAMPS-TC, ECMWF, EPS, GFS, AND GEFS, WHICH SHOWS A SLOW TURN WESTWARD AFTER 72 HOURS AS THE LOW-LEVEL EASTERLY FLOW BECOMES THE DOMINANT STEERING MECHANISM FOR THE WEAKENING CYCLONE. THIS REPRESENTS A SIGNIFICANT SHIFT WEST COMPARED TO THE PREVIOUS FORECAST, DUE TO A GROWING MODEL CONSENSUS IN THE WESTWARD TURN.

24S(HABANA). THERE IS MODERATE CONFIDENCE IN THE TRACK FORECAST, DUE TO  SOME UNCERTAINTY IN THE EXACT TIMING AT WHICH THE VORTEX WILL BECOME  DECOUPLED FROM DEEP CONVECTION AND MAKE ITS WESTWARD TURN.
24S(HABANA). THERE IS MODERATE CONFIDENCE IN THE TRACK FORECAST, DUE TO SOME UNCERTAINTY IN THE EXACT TIMING AT WHICH THE VORTEX WILL BECOME DECOUPLED FROM DEEP CONVECTION AND MAKE ITS WESTWARD TURN.

24S(HABANA). ENHANCED INFRARED IMAGERY INDICATES A WELL-DEFINED, CLEAR EYE  SURROUNDED BY A CENTRAL DENSE OVERCAST THAT HAS BEEN PERIODICALLY  BROKEN IN THE WESTERN SEMICIRCLE, POSSIBLY DUE TO DRY ENTRAINMENT AS  UPPER-LEVEL WINDS BEGIN TO BECOME WESTERLY.
24S(HABANA). ENHANCED INFRARED IMAGERY INDICATES A WELL-DEFINED, CLEAR EYE SURROUNDED BY A CENTRAL DENSE OVERCAST THAT HAS BEEN PERIODICALLY BROKEN IN THE WESTERN SEMICIRCLE, POSSIBLY DUE TO DRY ENTRAINMENT AS UPPER-LEVEL WINDS BEGIN TO BECOME WESTERLY.

24S(HABANA). 11/2019UTC. MICROWAVE DATA DEPICT A VERY COMPACT AND WELL ORGANIZED SYSTEM .
24S(HABANA). 11/2019UTC. MICROWAVE DATA DEPICT A VERY COMPACT AND WELL ORGANIZED SYSTEM .


24S(HABANA). 11/1929UTC. NOAA-20.
24S(HABANA). 11/1929UTC. NOAA-20.

24S(HABANA). THE 11/18UTC POSITION WAS  IDENTIFIED WITH HIGH CONFIDENCE BASED ON THE 11/1740UTC 37GHZ GMI  MICROWAVE IMAGE.
24S(HABANA). THE 11/18UTC POSITION WAS IDENTIFIED WITH HIGH CONFIDENCE BASED ON THE 11/1740UTC 37GHZ GMI MICROWAVE IMAGE.

24S(HABANA). 11/18UTC. CIMSS Vertical Shear Magnitude : 3.7 m/s ( 7.1 kts) Direction :  107.3 deg Experimental Vertical Shear and TC Intensity Trend Estimates: NEUTRAL OVER 24H.
24S(HABANA). 11/18UTC. CIMSS Vertical Shear Magnitude : 3.7 m/s ( 7.1 kts) Direction : 107.3 deg Experimental Vertical Shear and TC Intensity Trend Estimates: NEUTRAL OVER 24H.
Rédigé par PATRICK HOAREAU le Vendredi 12 Mars 2021 à 02:35