IMAN Moderate Tropical Storm-9th Very Rapid Formation and Evolution

IMAN Moderate Tropical Storm-9th

Very Rapid Formation and Evolution



The South Indian Ocean has turned out to be dynamic during Summer Season 2020-2021. ALICIA, BONGOYO, CHALAN, DANILO, ELOISE, FARAJI, GUAMBE and HABANA Cyclones have cruised in this Zone. MARIAN formed in the Area of Responsibility (AOR) of Australia but has popped up in the AOR of Mauritius Meteorological Services (MMS) and is still moving towards the Kangaroo Land.


At present, there are 3 Weather Systems which are still prevailing, the most recent one being IMAN Moderate Tropical Storm. The later has been named by the MMS in the early hours of Sunday 07 March 2021. It is very noticeable that IMAN is tracking towards the East South-East at the phenomenal speed of 30 kph. Although IMAN does not represent a direct threat to the Mascarene Islands, it is triggering lots of Rains.


The Mauritius Meteorological Services (MMS) has been indicating the formation of a Low Pressure, Disturbance and Depression in the Mozambique Channel a few days earlier. The MMS released its Weather Bulletin yesterday issued at 1645 hours on 06 March 2021 mentioning a Heavy Rain and Strong Wind Warning.’  See below.


[[[Special Weather Bulletin


Sat, Mar 6, 2021

Heavy Rain and Strong Wind Warning issued at 1645 hours on 06 March 2021

A Heavy Rain and Strong Wind Warning will be in force in Mauritius as from 0400 hours on Sunday 07 March 2021 and will be valid until 10.00 hours on Monday 08 March 2021. 


At 1600 hours the tropical disturbance was centred near latitude 20.5 degrees south and longitude 50.7 degrees east, that is, at about 750 km almost to the west of Le Morne. It is moving east-south-east at a speed of about 25 km/h.


Evolving in a favourable environment, the tropical disturbance will intensify rapidly into a tropical depression. Most weather models are strengthening it into a moderate tropical storm by tomorrow morning while continuing to move towards the east-southeast. On this trajectory the storm will pass at a distance of about 270 to 300 km to the south-southwest of Baie du Cap on Sunday mid-day. A convergence line associated with the storm will cross Mauritius on Sunday.  


The weather will become gradually cloudy to overcast as from tonight with few passing showers. The showers will spread over the whole Island becoming moderate to locally heavy with thunderstorms as from Sunday morning. Short duration high intensity rainfall may cause water accumulation in low lying areas.  

Wind will strengthen gradually, blowing from the northwest at a speed of 45 km/h, with gusts of 90 km/h


The public and especially the pilgrims heading towards Grand Bassin is advised to take all precautions due to multiple outdoor risks, namely heavy rain causing water accumulation, thunderstorm, strong winds. 


The fisherman community and the general public is also reminded that the sea will become very rough with north-westerly swells of 3-4 metres as from tomorrow. Ventures at sea are not advised.]]] 



[[[Special Weather Bulletin

Sun, Mar 7, 2021


Heavy Rain and Strong Wind Warning issued at 0430 hours on 07 March 2021

A Heavy Rain and Strong Wind Warning is in force in Mauritius and is valid until 0400 hours on Monday 08 March 2021


During the night, the tropical depression has intensified rapidly into a moderate tropical storm and was named IMAN by the meteorological services of Madagascar. At 04.00 hours this morning, moderate tropical storm IMAN was centred near latitude 22.6 degrees south and longitude 54.5 degrees east, that is, at about 370 km almost to the southwest of Le Morne. It is moving in an east-southeast direction at a speed of about 30 km/h

On this trajectory the storm will pass at a distance of about 270 to 300 km to the south-southwest of Baie du Cap by mid-morning. Rather active clouds associated with the moderate tropical storm will influence weather over Mauritius.


The sky will be cloudy to overcast with scattered showers at first. The showers will spread over the whole Island becoming moderate to locally heavy with thunderstorms. Short duration high intensity rainfall may cause water accumulation in low lying areas.  

Wind will strengthen gradually, blowing from the northwest at a speed of 45 km/h, with gusts of 90 km/h.


The public and especially the pilgrims heading towards Grand Bassin is advised to take all precautions due to multiple outdoor risks, namely heavy rain causing water accumulation, thunderstorm, strong winds.


The sea will become very rough with swells from the western sector of 3-4 metres. The fisherman and the general public are advised not to ventures at sea.]]] 



Rainfalls recorded by MMS has been Light as at 10 am Sunday 07 March 2021, maximizing to 13.5 mm; Maximum Wind Force varies from 25 to 58 kph and Humidity reached 95 %.  


Reunion Island is under a Vigilance since yesterday 06 March 2021. As at 8.00 am Sunday 07 March 2021, recorded Rainfalls are as follows:


Belle Combe-294 mm; Plaine Des Palmistes-235.3 mm ; Belle Vue Panon-207.1 mm ; Piton Ste. Rose-147.4 mm; Cilaos-145.1 mm; Piton Maido-141.2 mm and St. Benoit-140.2 mm, mainly.


As the Regional Specialized Meteorological Centre (RSMC), Météo-France-Réunion published its Advisories as from 06 March 2021:


{{{WTIO31 FMEE 060023

CMRS / CENTRE DES CYCLONES TROPICAUX DE LA REUNION

BULLETIN D'ANALYSE ET DE PREVISION CYCLONIQUE (SUD-OUEST OCEAN INDIEN)


0.A NUMERO DU BULLETIN : 7/14/20202021

1.A DEPRESSION SUR TERRE 14

1.B PREVISIONS (EXTENSIONS DES VENTS FORTS EN KM):


12H: 06/03/2021 12 UTC: 20.1 S / 50.5 E, VENT MAX= 025 KT, PERTURBATION TROPICALE.


24H: 07/03/2021 00 UTC: 22.1 S / 53.6 E, VENT MAX= 035 KT, TEMPETE TROPICALE MODEREE

28 KT NE: 85 SE: 65 SO: 75 NO: 85

34 KT NE: 75 SE: 10 SO: 65 NO: 65


36H: 07/03/2021 12 UTC: 23.5 S / 56.2 E, VENT MAX= 040 KT, TEMPETE TROPICALE MODEREE

28 KT NE: 100 SE: 100 SO: 95 NO: 150

34 KT NE: 95 SE: 95 SO: 85 NO: 110


48H: 08/03/2021 00 UTC: 24.8 S / 58.2 E, VENT MAX= 035 KT, TEMPETE TROPICALE MODEREE

28 KT NE: 100 SE: 110 SO: 100 NO: 100

34 KT NE: 95 SE: 65 SO: 95 NO: 75


60H: 08/03/2021 12 UTC: 26.2 S / 60.0 E, VENT MAX= 035 KT, DEPRESSION POST-TROPICALE

28 KT NE: 120 SE: 95 SO: 130 NO: 150

34 KT NE: 110 SE: 85 SO: 120 NO: 65


72H: 09/03/2021 00 UTC: 27.2 S / 61.3 E, VENT MAX= 030 KT, DEPRESSION POST-TROPICALE

28 KT NE: 85 SE: 95 SO: 175 NO: 150


2.B TENDANCE ULTERIEURE:


96H: 10/03/2021 00 UTC: 29.0 S / 62.3 E, VENT MAX= 025 KT, DEPRESSION SE COMBLANT


120H: 11/03/2021 00 UTC: 30.0 S / 62.8 E, VENT MAX= 020 KT, DEPRESSION RESIDUELLE


2.C COMMENTAIRES:


LE SYSTEME EVOLUE TOUJOURS SUR TERRE EN CONTINUANT SA TRAVERSEE DE MADAGASCAR. LA CONVECTION RESTE PRES DU CENTRE DE CIRCULATION. SUR LES DERNIERES IMAGES SATELLITE, LA COHERENCE DE LA CIRCULATION EST PLUS CLAIREMENT AFFECTEE. LA DIVERGENCE RESTE EXCELLENTE COTE POLAIRE. LE SYSTEME DEVRAIT RESSORTIR EN MER AU SUD DE TAMATAVE EN FIN DE MATINEE, AVANT DE CONTINUER SA TRAJECTOIRE VERS LE SUD-EST A L'AVANT D'UN THALWEG DES MOYENNES LATITUDES. LA MAJORITE DES GUIDANCES LE FONT ALORS PASSER A PLUS DE 100 KM AU SUD-OUEST DE LA REUNION DIMANCHE EN DEBUT DE MATINEE, MEME S'IL EXISTE ENCORE UN PEU D'INCERTITUDE SUR SA TRAJECTOIRE EXACTE.


EN DEBUT DE SEMAINE PROCHAINE, LE SYSTEME DEVRAIT

ETRE CAPTURE PAR UN TALWEG DES MOYENNES LATITUDES L'EVACUANT AU SUD DE 25S, LOIN DES TERRES HABITEES, SUR UNE TRAJECTOIRE SUD-EST PUIS SUD-SUD-EST. EN TOUTE FIN DE PERIODE, LA DEPRESSION RESIDUELLE POURRAIT RESTER TEMPORAIREMENT PIEGEE AU NORD DE 30S AVEC L'ARRIVEE D'UN NOUVEL ANTICYCLONE PAR L'OUEST.


EN RESSORTANT SUR MER DEMAIN, LE SYSTEME DEVRAIT RENCONTRER DES CONDITIONS DEVENANT PROGRESSIVEMENT PLUS BAROCLINES EN INTERACTION AVEC UNE BRANCHE DU JET SUBTROPICAL. DANS UN PREMIER TEMPS, IL DEVRAIT S'INTENSIFIER DE NOUVEAU POUR ATTEINDRE LE STADE DE TEMPETE TROPICALE D'ICI DIMANCHE EN SE DEPLACANT RAPIDEMENT DANS LE SENS DU FLUX DE MOYENNE ET HAUTE ALTITUDE. A PARTIR DE LUNDI, LA HAUSSE DU CISAILLEMENT

ET LE PASSAGE SUR DES EAUX PLUS FROIDES AURONT TENDANCE A LE FAIRE EVOLUER EN SYSTEME POST-TROPICAL TOUT EN L'AFFAIBLISSANT.


EN TERMES D'IMPACT POUR MADAGASCAR, LES PLUIES AU COURS DES

PROCHAINES 24H POURRAIENT ATTEINDRE DES CUMULS DE 100 A 150 MM LOCALEMENT SUR LA PARTIE NORD DU PAYS. POUR LES MASCAREIGNES, ON ATTEND UNE DEGRADATION PLUVIEUSE ET VENTEUSE ASSEZ BREVE (EN PARTICULIER LA REUNION), ENTRE SAMEDI SOIR ET DIMANCHE MIDI.}}}


Watch LIVE from MMS.


PKANHYE.    Uploaded: 12.13 pm SUNDAY 07 MARCH 2021.


Satellite Animation