Subtropical Storm Ubá was the fourth

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

subtropical cyclone A subtropical cyclone is a weather system that has some characteristics of both tropical cyclone, tropical and extratropical cyclones. As early as the 1950s, meteorologists were uncertain whether they should be characterized as Tropical cyclone ...

to form in the

South Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for ...

Ocean in 2021. Ubá originated from an

area of low pressure In meteorology, a low-pressure area (LPA), low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. It is the opposite of a high-pressure area. Low-pressure areas are commonly associated with inclem ...

that formed off the coast of

Rio de Janeiro Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

and evolved into a subtropical cyclone on 10 December. The cyclone lingered for two days, before weakening back to a low-pressure area and dissipating on 13 December. Together with the South Atlantic Convergence Zone (SACZ), Ubá caused heavy rains in

Minas Gerais Minas Gerais () is one of the 27 federative units of Brazil, being the fourth largest state by area and the second largest in number of inhabitants with a population of 20,539,989 according to the 2022 Brazilian census, 2022 census. Located in ...

, in

Espírito Santo Espírito Santo (; ) is a state in southeastern Brazil. Its capital is Vitória, and its largest city is Serra. With an extensive coastline, the state hosts some of the country's main ports, and its beaches are significant tourist attracti ...

and mainly in

Bahia Bahia () is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo (state), São Paulo, Mina ...

. The storm became the deadliest South Atlantic (sub)tropical cyclone, with a death toll of 15.

Meteorological history

The low-pressure system formed off the coast of

and evolved into a subtropical cyclone. The low caused, along with the South Atlantic Convergence Zone, heavy rains in Minas Gerais, in Espírito Santo and mainly in Bahia where very high volumes of precipitation were recorded in the city of

Itamaraju Itamaraju is a municipality in the state of Bahia in the North-East region of Brazil. "Itamaraju" is a word from the Tupi language meaning "rock of the trees of Jucuruçu" from the terms itá (rock), mara (woods), and ju (first syllable of the ...

, measuring . More than 30 municipalities in Bahia decreed state of emergency because of heavy rains and ten people died in the state. On 10 December, the cyclone evolved and gave rise to a subtropical depression on the coast of southern Brazil, according to a synoptic chart from the

Brazilian Navy The Brazilian Navy () is the navy, naval service branch of the Brazilian Armed Forces, responsible for conducting naval warfare, naval operations. The navy was involved in War of Independence of Brazil#Naval action, Brazil's war of independence ...

. In the morning of the same day, according to the CHM, the system evolved into a subtropical storm and was named ''Ubá''. On 12 December, the system was lowered to a subtropical depression upon exiting METAREA V and a day later, encountering cooler waters and of wind shear, it was lowered again to a low pressure common at sea.

Impact

Floods in Minas Gerais

In the Jequitinhonha Valley, in Minas Gerais, the rain caused by ZCAS and this subtropical cyclone caused flooding, with the Jucuruçu River overflowing. Another 5 deaths from these systems were reported., a dam overflowed in

Crisólita Crisólita is a municipality in the northeast of the Brazilian state of Minas Gerais. the population was 6,760 in a total area of 970 km². The elevation is 282 meters. It is part of the IBGE statistical microregion of Nanuque. The ...

and in the city of Monte Formoso, were registered . 31 cities in Minas Gerais were in a state of emergency.

Floods in southern Bahia

The floods in southern

began on 7 December 2021, with heavy rains that hit the region. Among the most affected cities in south of the state are

Eunápolis Eunápolis is a municipality in Bahia Bahia () is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (a ...

and

Itabela Itabela is a municipality in the state of Bahia in the North-East region of Brazil. See also *List of municipalities in Bahia This is a list of the municipalities in the state of Bahia (BA), located in the Northeast Region of Brazil. Bahia ...

, where a strong rise in river levels and slides of land. Other cities are also being affected, requiring air assistance to rescue and supply basic items. In

Ilhéus Ilhéus () is a major city located in the southern coastal region of Bahia, Brazil, 211 km south of Salvador, Brazil, Salvador, the state's capital. The city was founded in 1534 as Vila de São Jorge dos Ilhéus and is known as one of the mos ...

, the pool of a luxury resort overflowed, and some guests had to be transferred to another hotel The government of Bahia decreed an emergency situation in 24 municipalities on the 9th. News of deaths and disappearances circulated in the media, more than a thousand displaced people are estimated.

References

External links

{{DEFAULTSORT:Subtropical Storm Ubá 2021 meteorology

Ubá Ubá is a Municipalities of Brazil, municipality located in the Zona da Mata (Minas Gerais), Zona da Mata Mesoregion (Brazil), mesoregion of Minas Gerais, Brazil, southeast of Belo Horizonte, and north of Rio de Janeiro. The estimated populatio ...

South Atlantic tropical cyclones Tropical cyclones in Brazil