The arrival of a new cold front in the South Region, associated with the large-scale presence of soot in the atmosphere, may cause a phenomenon known as “black rain” in some locations in the south and southeast of the country. The National Institute of Meteorology (Inmet) warns that this water may contain contaminants, making it unsuitable for consumption and harmful to the environment.
According to Inmet, the black rain should mainly affect Rio Grande do Sul, Santa Catarina and Paraná, but it could extend to other areas, as it advances to the south of Mato Grosso do Sul and the Southeast.
Meteorologists explain that the mixture of soot caused by the fires in Brazil, with the humidity coming from the cold front coming from Argentina and Paraguay, tends to cause the phenomenon – a kind of washing of the dirt that rose into the atmosphere, dumping all this material on the surface, affecting soil, rivers and vegetation.
Weather forecast
The next few days will see rain in the South Region, moving to areas of São Paulo and the extreme south of the Central-West Region. The central area of the country, however, will continue to experience high temperatures and dry weather, reported Inmet.
“Two regions will experience changes in the coming days in the South and Southeast. In the South, areas of instability related to hot and humid air originating in Argentina and Paraguay will be observed. Initially, this new formation will affect Rio Grande do Sul and Santa Catarina, intensifying rains during the night,” Inmet meteorologist Heráclio Alves explained to Agência Brasil.
This new cold front will then become more intense and extend to Paraná and the south of Mato Grosso do Sul. “In Santa Catarina, this increase in intensity will occur from Saturday, and on Sunday it will affect the south of Paraná and Mato Grosso do Sul,” added the meteorologist.
In the South Region, the rain will only begin to decrease between Saturday (14) and Sunday (15), when the front will move to the state of São Paulo and other areas of the Southeast. The expectation is that, between Sunday and Monday (16), the front will concentrate more in the east of São Paulo and in the Atlantic, hitting both the capital and the coast of São Paulo, as early as Monday.
Central core
In other regions of the country, the mass of hot and dry air will predominate. The sky will have few clouds. “This reduced cloud cover means very little chance of rain in the central core of the country, which will have high temperatures of 41 degrees Celsius (ºC) in some areas of the Center-West and North of Brazil,” said Alves.
According to the meteorologist, the highest temperatures will be observed in the south of Maranhão and Pará, as well as in Mato Grosso, Tocantins and in the center, where drought is already occurring.
“In addition to high temperatures, we will have very low humidity levels, which could reach less than 15% in some locations. This dry and hot air in the central core will remain throughout the week,” added the meteorologist.
