SOUTH INDIAN: 24S(HABANA) set to re-intensify after 48hours and 25S(IMAN) analysed at 45knots, 07/21utc updates


24S(HABANA) AND 25S(IMAN). ON THE RIGHT END 24S LOST IT EYE FEATURE WHICH HAS BEEN BACK RECENTLY. 25S HAS INTENSIFIED BUT HAS A SHEARED PATTERN. CLICK TO ANIMATE IF NEEDED.


24S(HABANA) AND 25S(IMAN). ON THE RIGHT END 24S LOST IT EYE FEATURE WHICH HAS BEEN BACK RECENTLY. 25S HAS INTENSIFIED BUT HAS A SHEARED PATTERN. CLICK TO ANIMATE IF NEEDED.
24S(HABANA) AND 25S(IMAN). ON THE RIGHT END 24S LOST IT EYE FEATURE WHICH HAS BEEN BACK RECENTLY. 25S HAS INTENSIFIED BUT HAS A SHEARED PATTERN. CLICK TO ANIMATE IF NEEDED.
2021 MAR 07 21UTC #SOUTHERNHEMISPHERE
TC #24S #HABANA  #SOUTHINDIANOCEAN
WARNING 8
As of 18:00 UTC Mar 07, 2021:
Location: 17.4°S 80.4°E
Maximum Winds: 100 kt (185km/h)
Gusts: 125 kt ( 230km/h)
Minimum Central Pressure: 960 mb
CATEGORY US: 3
LOCATED AT 07/18UTC 1820KM APPROXIMATELY KM EAST-NORTHEAST OF RODRIGUES ISLAND HAS TRACKED SOUTHEASTWARD AT 07KM/H OVER THE PAST 6 HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS
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TC #25S #(IMAN)   #SOUTHINDIANOCEAN
WARNING 1
As of 18:00 UTC Mar 07, 2021:
Location: 24.4°S 58.0°E
Maximum Winds: 45 kt ( 85km/h)
Gusts: 55 kt ( 100km/h)
Minimum Central Pressure: 991 mb
LOCATED AT 07/18UTC APPROXIMATELY 515 KM SOUTH-SOUTHEAST OF ST DENIS, LA REUNION, HAS TRACKED EAST-
SOUTHEASTWARD AT 35 KM/H OVER THE PAST SIX HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS


Cheers,
Patrick Hoareau
 Météo974
M974World
Cyclone Class 4
 Cheers,PH.

Joint Typhoon Warning Center

24S(HABANA).WARNING 8 ISSUED AT 07/21UTC.TC 24S HAS WEAKENED STEADILY OVER THE PAST TWELVE HOURS, AND  TEMPORARILY LOST ITS EYE, UNDER THE INFLUENCE OF A SHORT-TERM  INCREASE IN VERTICAL WIND SHEAR AND COOLING OCEAN WATER BENEATH THE  SLOW-MOVING SYSTEM. TC 24S IS TURNING POLEWARD UNDER THE INFLUENCE  OF A SHIFTING STEERING PATTERN, WITH SUBTROPICAL RIDGING BUILDING TO  THE EAST. VERTICAL WIND HAS EASED A BIT OVER THE PAST SIX HOURS (10- 15 KTS), SEA SURFACE TEMPERATURES ARE MODERATELY FAVORABLE (26-28C)  AND STRONG POLEWARD OUTFLOW IS EVIDENT IN SATELLITE-DERIVED, UPPER- LEVEL WIND VECTOR DATA. TC 24S IS EXPECTED TO TURN WESTWARD OVER THE  NEXT 24 TO 36 HOURS AS SUBTROPICAL RIDGING BUILDS TO THE SOUTH AND  TAKES OVER AS THE DOMINANT STEERING MECHANISM. THE SYSTEM WILL  CONTINUE FOLLOWING THE FLOW ASSOCIATED WITH THIS RIDGE, TURNING  POLEWARD BY 120H. FURTHER NEAR-TERM WEAKENING IS EXPECTED BEFORE  PASSAGE OVER WARM WATER, ROBUST OUTFLOW AND LOW VERTICAL WIND SHEAR  DRIVE A DISTINCT INTENSIFICATION TREND WITH POSSIBLE RAPID  INTENSIFICATION AFTER 36H.
24S(HABANA).WARNING 8 ISSUED AT 07/21UTC.TC 24S HAS WEAKENED STEADILY OVER THE PAST TWELVE HOURS, AND TEMPORARILY LOST ITS EYE, UNDER THE INFLUENCE OF A SHORT-TERM INCREASE IN VERTICAL WIND SHEAR AND COOLING OCEAN WATER BENEATH THE SLOW-MOVING SYSTEM. TC 24S IS TURNING POLEWARD UNDER THE INFLUENCE OF A SHIFTING STEERING PATTERN, WITH SUBTROPICAL RIDGING BUILDING TO THE EAST. VERTICAL WIND HAS EASED A BIT OVER THE PAST SIX HOURS (10- 15 KTS), SEA SURFACE TEMPERATURES ARE MODERATELY FAVORABLE (26-28C) AND STRONG POLEWARD OUTFLOW IS EVIDENT IN SATELLITE-DERIVED, UPPER- LEVEL WIND VECTOR DATA. TC 24S IS EXPECTED TO TURN WESTWARD OVER THE NEXT 24 TO 36 HOURS AS SUBTROPICAL RIDGING BUILDS TO THE SOUTH AND TAKES OVER AS THE DOMINANT STEERING MECHANISM. THE SYSTEM WILL CONTINUE FOLLOWING THE FLOW ASSOCIATED WITH THIS RIDGE, TURNING POLEWARD BY 120H. FURTHER NEAR-TERM WEAKENING IS EXPECTED BEFORE PASSAGE OVER WARM WATER, ROBUST OUTFLOW AND LOW VERTICAL WIND SHEAR DRIVE A DISTINCT INTENSIFICATION TREND WITH POSSIBLE RAPID INTENSIFICATION AFTER 36H.

24S(HABANA). WITH THE EXCEPTION OF THE NAVGEM  TRACK, WHICH LIES SLIGHTLY TO THE SOUTH OF THE ENVELOPE, AND THE  ECMWF ENSEMBLE MEAN, WHICH LIES SLIGHTLY TO THE NORTH OF THE MODEL  ENVELOPE, NUMERICAL MODEL GUIDANCE IS IN VERY GOOD AGREEMENT,  LENDING HIGH CONFIDENCE TO THE CURRENT JTWC FORECAST TRACK.
24S(HABANA). WITH THE EXCEPTION OF THE NAVGEM TRACK, WHICH LIES SLIGHTLY TO THE SOUTH OF THE ENVELOPE, AND THE ECMWF ENSEMBLE MEAN, WHICH LIES SLIGHTLY TO THE NORTH OF THE MODEL ENVELOPE, NUMERICAL MODEL GUIDANCE IS IN VERY GOOD AGREEMENT, LENDING HIGH CONFIDENCE TO THE CURRENT JTWC FORECAST TRACK.

24S(HABANA). 07/2045UTC. THE EYE FEATURE IS CLEARLY APPARENT ONCE AGAIN SINCE 07/2015UTC.
24S(HABANA). 07/2045UTC. THE EYE FEATURE IS CLEARLY APPARENT ONCE AGAIN SINCE 07/2015UTC.

24S(HABANA). 07/1637UTC. THE CURRENT POSITION IS SITUATED NEAR  A LOW-LEVEL CENTER FEATURE EVIDENT IN A 071637Z METOP-C ASCAT PASS.
24S(HABANA). 07/1637UTC. THE CURRENT POSITION IS SITUATED NEAR A LOW-LEVEL CENTER FEATURE EVIDENT IN A 071637Z METOP-C ASCAT PASS.

24S(HABANA). CIMSS Vertical Shear Magnitude : 6.6 m/s (12.8 kts) Direction :   34.4 deg CIMSS Experimental Vertical Shear and TC Intensity Trend Estimates: NEUTRAL OVER 24H
24S(HABANA). CIMSS Vertical Shear Magnitude : 6.6 m/s (12.8 kts) Direction : 34.4 deg CIMSS Experimental Vertical Shear and TC Intensity Trend Estimates: NEUTRAL OVER 24H

25S(IMAN). NUMERICAL  MODEL GUIDANCE IS IN EXCELLENT AGREEMENT REGARDING THE FORECAST  TRACK, WHICH IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH HIGH  CONFIDENCE.
25S(IMAN). NUMERICAL MODEL GUIDANCE IS IN EXCELLENT AGREEMENT REGARDING THE FORECAST TRACK, WHICH IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE.

25S(IMAN). WARNING 1 ISSUED AT 07/21UTC.25S(IMAN) HAS CONSOLIDATED AND INTENSIFIED OVER THE PAST SIX HOURS WHILE  TRACKING EAST-SOUTHEASTWARD IN THE GRADIENT BETWEEN SUBTROPICAL  RIDGING TO THE NORTHEAST AND AN APPROACHING, DEEP-LAYER TROUGH TO  THE SOUTHWEST. THE SYSTEM IS EXPECTED TO CONTINUE TRACKING GENERALLY  SOUTHEASTWARD OVER THE NEXT 36 HOURS AND COMPLETE EXTRATROPICAL  TRANSITION AS THE APPROACHING TROUGH OVERTAKES THE SYSTEM. WHILE  POLEWARD OUTFLOW IS STRONG AND SEA SURFACE TEMPERATURE IS MARGINALLY  FAVORABLE AT AROUND 27C, VERTICAL WIND SHEAR IS VERY HIGH (GREATER  THAN 30 KNOTS). THE CONTINUED IMPACT OF STRONG VERTICAL WIND SHEAR  AND PASSAGE OVER COOL WATER ARE EXPECTED TO WEAKEN THE SYSTEM  THROUGHOUT THE FORECAST PERIOD, WITH NO OFFSETTING BAROCLINIC  SUPPORT FROM INTERACTION WITH THE AFOREMENTIONED TROUGH.
25S(IMAN). WARNING 1 ISSUED AT 07/21UTC.25S(IMAN) HAS CONSOLIDATED AND INTENSIFIED OVER THE PAST SIX HOURS WHILE TRACKING EAST-SOUTHEASTWARD IN THE GRADIENT BETWEEN SUBTROPICAL RIDGING TO THE NORTHEAST AND AN APPROACHING, DEEP-LAYER TROUGH TO THE SOUTHWEST. THE SYSTEM IS EXPECTED TO CONTINUE TRACKING GENERALLY SOUTHEASTWARD OVER THE NEXT 36 HOURS AND COMPLETE EXTRATROPICAL TRANSITION AS THE APPROACHING TROUGH OVERTAKES THE SYSTEM. WHILE POLEWARD OUTFLOW IS STRONG AND SEA SURFACE TEMPERATURE IS MARGINALLY FAVORABLE AT AROUND 27C, VERTICAL WIND SHEAR IS VERY HIGH (GREATER THAN 30 KNOTS). THE CONTINUED IMPACT OF STRONG VERTICAL WIND SHEAR AND PASSAGE OVER COOL WATER ARE EXPECTED TO WEAKEN THE SYSTEM THROUGHOUT THE FORECAST PERIOD, WITH NO OFFSETTING BAROCLINIC SUPPORT FROM INTERACTION WITH THE AFOREMENTIONED TROUGH.


25S(IMAN). 07/2015UTC.
25S(IMAN). 07/2015UTC.

25S(IMAN). THE CURRENT  POSITION AND INTENSITY ARE BASED ON A 071724Z METOP-B ASCAT PASS WHICH READ 45KNOT WINDS.
25S(IMAN). THE CURRENT POSITION AND INTENSITY ARE BASED ON A 071724Z METOP-B ASCAT PASS WHICH READ 45KNOT WINDS.


07/21UTC. JTWC IS ISSUING 12HOURLY WARNINGS ON 24S(HABANA) AND 25S(IMAN). 3HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS. THEY WERE DISCONTINUED FOR 23P(NIRAN) AND 22S(MARIAN).
07/21UTC. JTWC IS ISSUING 12HOURLY WARNINGS ON 24S(HABANA) AND 25S(IMAN). 3HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS. THEY WERE DISCONTINUED FOR 23P(NIRAN) AND 22S(MARIAN).
Rédigé par PATRICK HOAREAU le Lundi 8 Mars 2021 à 02:00