Intense Tropical Cyclone Herold was a powerful

tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

that affected

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

and the

Mascarene Islands The Mascarene Islands (, ) or Mascarenes or Mascarenhas Archipelago is a group of islands in the Indian Ocean east of Madagascar consisting of islands belonging to the Republic of Mauritius as well as the French department of Réunion. Their na ...

in March 2020. Herold was the tenth zone of disturbed weather, ninth depression, eighth moderate tropical storm, sixth severe tropical storm, fifth

, and second intense tropical cyclone of the slightly above-average 2019–20 South-West Indian Ocean cyclone season. Herold formed on 13 March from a disorganized area of low pressure near

Tromelin Island Tromelin Island (; , ), once called the Isle of Sand, is a low, flat island in the Indian Ocean about north of Réunion and about east of Madagascar. Both France and Mauritius claim sovereignty over the islands, and France includes it in t ...

.http://www.meteo.fr/temps/domtom/La_Reunion/webcmrs9.0/francais/activiteope/bulletins/zcit/ZCITF_202003011000.pdf When Herold reached Madagascar, it caused five deaths and an unknown amount of damage. Thousands of homes were flooded in the northeastern region.

Maroantsetra Maroantsetra , formerly Louisbourg, is a market town and domestic seaport in Analanjirofo Region, Madagascar, at the northern end of the Bay of Antongil. In 2018, Maroantsetra counted 42,529 people. Even though it is a small city, Maroantsetra ...

got the worst of Herold, with all five deaths it caused coming from there.

Meteorological history

Early in March 2020, an area of low pressure existed near

, but it dissipated on 4 March. It unexpectedly regenerated the next day near the Mascarene Islands. Météo France predicted it would strengthen into a tropical depression by the end of the week. Over the next two weeks, it gradually gained convection, until on 13 March, Zone of Disturbed Weather 10 formed northwest of

. The next day, the JTWC and MFR upgraded it to a tropical depression. Late on 14 March, 10 reached moderate tropical storm intensity and was named ''Herold''. The JTWC began tracking it as Tropical Cyclone 22S. Herold began to undergo slow intensification. At 18:00 UTC on 15 March, the cyclone was designated Tropical Cyclone Herold. Late on March 17, Herold reached its peak intensity as an Intense tropical cyclone, and the JTWC classified it as a Category 3-equivalent tropical cyclone. As this happened, Herold rapidly moved southeast, Herold's peak intensity was short-lived. On 18 March, Herold began rapidly weakening. Later that day, Herold became extratropical. Finally, on 20 March, Herold dissipated entirely.

Preparations

Madagascar

The first alert, a green alert (issued two to five days before the storm's potential impact), was issued on March 13 by Météo Madagascar for the areas in northeastern Madagascar. The next day, the alert was upgraded to a yellow alert (issued one to two days before storm, storm is going to be damaging area but it has not truly happened yet).

Mascarene Islands

On 18 March, a class four cyclone warning was issued for

Rodrigues Rodrigues ( ; Mauritian Creole, Creole: ) is a Autonomous administrative division, autonomous Outer islands of Mauritius, outer island of the Republic of Mauritius in the Indian Ocean, about east of Mauritius. It is part of the Mascarene Isl ...

Impact

Madagascar

Heavy rain was recorded in northeastern Madagascar on 13 March. fell on

Sambava Sambava is a city and commune (commune urbaine; ) at the east coast of northern Madagascar. It is the capital of Sambava District and Sava Region. The population of the commune was 84,039 in as of the 2018 commune census. Infrastructure Sambav ...

that same day. Intense flooding occurred in the Ankavanana River, which threatened more than 1000 people. Five people were killed in the

Sava Region Sava is a Regions of Madagascar, region in northern Madagascar. Its capital is Sambava. Until 2009 Sava belonged to Antsiranana Province. The region is situated at the northern part of the east coast of Madagascar. It is bordered by the region Dian ...

. Flooding impacted more than 100 schools. Homes were swept away in areas near

.16 March 2020
"Top News: Tropical Cyclone Herold drenches northeastern Madagascar"
Retrieved 24 March 2020. Near the Andranofotsy River, people were most affected. By 17 March, though, the water level had decreased a fair amount in the community.16 March 2020
"Herold floods Maroantsetra"
Retrieved 25 March 2020. That day, the water level on land rose to . 13 of 20 municipalities in the

district were underwater and 28 houses had been destroyed in the town of Mahalevona. In Maroantsetra, 104 homes were affected by the

storm surge A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the ...

. A school in Anjanazana was found with puddles of mud in its classrooms. The effects of Herold didn't end until the cyclone alerts were lifted on 17 March for the entire island. 911 homes were flooded. 178 huts were damaged, and 127 residencies were destroyed in Madagascar. In Maroantsetra, 79 classrooms were damaged, and 24 were damaged in Sainte-Marie.

Mascarene Islands

In the Mascarene Islands, maximum sustained winds of was recorded. When Herold passed in between the islands of

Mauritius Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Ag ...

and

on 17 March, it made schools close and caused eighty people to seek refuge in accommodation centers. In the islands, damage was minimal. In most areas, it was limited to downed trees and power outages. However, a gust of was recorded in Sir Gaëtan Duval Airport. Maximum rainfall was no more than . Herold also briefly passed over

Réunion Réunion (; ; ; known as before 1848) is an island in the Indian Ocean that is an overseas departments and regions of France, overseas department and region of France. Part of the Mascarene Islands, it is located approximately east of the isl ...

. There was no known damage there.16 March 2020
"NASA's Aqua satellite snaps new image of Cyclone Herold"
Retrieved 23 April 2020.

References

{{DEFAULTSORT:Herold 2019–20 South-West Indian Ocean cyclone season Intense Tropical Cyclones Cyclones in Madagascar Tropical cyclones in 2020

Meteorological history

Preparations

Madagascar

Mascarene Islands

Impact

Madagascar

Mascarene Islands

See also

References