Cyclone brings cold to the South and rain to Matopiba.

The formation of an extratropical cyclone near the coast of the Southern Region between Friday (16) and Saturday (17) should intensify winds on the coast and favor the arrival of a cold air mass to the south-central region of Brazil, according to a forecast released by the National Institute of Meteorology (Inmet). The system should also influence rainfall in other regions, with the possibility of the formation of the first South Atlantic Convergence Zone (ZCAS) of the season and increased rainfall in Matopiba.

The cold front associated with the cyclone is expected to move through the Southeast and Central-West regions and reach areas of Matopiba, which includes Maranhão, Tocantins, Piauí, and Bahia. The combination of this system and atmospheric circulation at high levels may favor the formation of the South Atlantic Convergence Zone (SACZ) over the weekend, intensifying rainfall in this agricultural region.

According to Inmet's forecast, the instability should also affect the west and south of the North Region, with rainfall in Amazonas, southwestern Roraima, Acre, Rondônia, and Tocantins.

In the Northeast, rain is forecast for southern Maranhão, southern Piauí, and western and southern Bahia. In the Central-West, rainfall is expected in Mato Grosso, Goiás, the Federal District, and the northern and eastern portions of Mato Grosso do Sul. In the Southeast, all states are expected to experience rain.

Conversely, the advance of cold air tends to reduce instability in the Southern Region. Temperatures are expected to drop, with nights below 10°C in some locations. Meanwhile, in the north and east of the Northern Region, including areas of Pará, Roraima, and Amapá, and in the north and east of the Northeast, the forecast is for predominantly hot and dry weather.

In the North Region, Friday (16) should be marked by instability mainly in the west and south. Amazonas, Rondônia, Acre, southern Pará and central and southern Tocantins may register showers and thunderstorms, with a yellow warning of potential danger for storms in these areas. In central Pará, northern Tocantins and Roraima, isolated showers may occur. In other areas, the weather should remain stable, including the capitals Macapá (AP) and Belém (PA).

Among the capitals of the region, Rio Branco (AC) will have a minimum of 24 °C. The heat will be intense in Boa Vista (RR), with a maximum of 37 °C, and in Belém (PA) and Palmas (TO), where thermometers can reach 36 °C. On Saturday (17), instabilities should persist in northern Rondônia, western Acre and in much of Amazonas and Tocantins, with showers and thunderstorms. There is also a possibility of isolated rain in central, southern and coastal Pará and in northern and eastern Amapá.

Inmet (National Institute of Meteorology) forecasts a yellow warning of potential danger for storms in western and southern Amazonas, southern Pará, and central and southern Tocantins. In other areas, the weather should be more stable, especially in southern Rondônia, northern and eastern Roraima, and northwestern Pará. Rio Branco will have a minimum temperature of 23°C, while Boa Vista could register a maximum of 37°C.

In the Northeast, unstable weather patterns are expected to move inland on Friday, bringing rain to central and southern Maranhão, southwestern Piauí, and much of Bahia. Western and southern Bahia may experience rainfall accompanied by thunderstorms, with a yellow warning indicating potential danger for storms, including areas near Salvador.

In the northern and eastern northeastern region, from the coast of Maranhão and Piauí to Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Sergipe, and Alagoas, the weather should remain sunny, with varying cloud cover and no rain forecast. There is also a yellow warning of potential danger due to low air humidity in areas of eastern Maranhão, central Piauí, central and southern Ceará, central and western Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, and Sergipe, as well as northern Bahia.

Among the capital cities, Maceió (AL) will have a minimum temperature of 22°C, while Teresina (PI) could reach 39°C. In the other northeastern capitals, the maximum temperatures should vary between 30°C and 32°C. On Saturday, rain is expected to continue in southern Maranhão, southern Piauí, and western, central, and southern Bahia, with showers and thunderstorms. The yellow warning for storms remains in effect for the aforementioned areas of Bahia.

In contrast, the coast of Maranhão, northern Piauí, Ceará, Rio Grande do Norte, Paraíba, and much of Pernambuco, as well as Alagoas and Sergipe, should have predominantly sunny and hot weather. Temperatures remain similar to those forecast for Friday, with a high of 39°C in Teresina.

In the Central-West region, Friday should bring rain to much of the area. Mato Grosso, Goiás, the Federal District, and Mato Grosso do Sul may experience showers and thunderstorms, although rainfall should be less intense in southern Mato Grosso do Sul. There is an orange warning for severe storms in southern Goiás and a yellow warning for potential danger in northwestern, northern, central, and eastern Mato Grosso, eastern Mato Grosso do Sul, the Federal District, and other areas of Goiás. Throughout the afternoon and especially at night, the rain should decrease in intensity in parts of the region. In Mato Grosso, isolated showers are expected. In the southwest and south of the state and in northwestern, northern, and eastern Mato Grosso do Sul, there is a possibility of isolated rain at night.

In southern Mato Grosso do Sul, especially in areas near the borders with Paraguay and Paraná, the weather should be more stable. In the Federal District and eastern Goiás, showers and thunderstorms are expected to persist throughout the night.

Temperatures are expected to drop. Campo Grande (MS) will have a minimum of 18°C and a maximum of 22°C. Cuiabá (MT) may reach 27°C, Brasília (DF) 28°C, and Goiânia (GO) 30°C. On Saturday, the arrival of drier and colder air should reduce cloud cover in much of the Central-West region. The weather will be sunny in central and southern Mato Grosso do Sul, while other areas of the state and southern and southwestern Mato Grosso and Goiás should have many clouds, but no rain is expected.

The weather will remain unstable in northeastern Goiás and the Federal District, with showers and thunderstorms. Isolated showers are also possible in northern and eastern Mato Grosso. There is a yellow warning for potential storm danger in northwestern, northern, and eastern Mato Grosso, central and northern Goiás, and the Federal District. Campo Grande will have temperatures between 16°C and 24°C. In Brasília, the maximum temperature should not exceed 26°C, while Cuiabá and Goiânia may reach 29°C.

In the Southeast, rain is expected to continue on Friday, accompanied by thunderstorms in all four states. The National Institute of Meteorology (Inmet) has issued an orange warning for dangerous storms in the Triângulo Mineiro region, central, southern and southeastern Minas Gerais, central and southern Espírito Santo, throughout Rio de Janeiro, and in the northern and eastern portions of São Paulo. The alert covers the four capital cities of the region. In other areas, there is a yellow warning for potentially dangerous storms. From the evening onwards, the arrival of drier and colder air should reduce the chances of rain in São Paulo and the Triângulo Mineiro region, although isolated showers may still occur.

Storms are expected to persist overnight in central, northern, and eastern Minas Gerais, Rio de Janeiro, and Espírito Santo. In São Paulo, the minimum temperature will be 15°C and the maximum 23°C. Belo Horizonte may reach 26°C, while Rio de Janeiro should register a maximum of 30°C. On Saturday, rain is expected to continue in northern and eastern Minas Gerais, Rio de Janeiro, and Espírito Santo, with a yellow warning for potential storm danger in these areas.

In São Paulo, the arrival of drier, colder air from the west should reduce cloud cover. Rainfall is expected to be concentrated in the east and along the coast, with less intensity. In other areas of São Paulo state and the Triângulo Mineiro region, the sun should appear among many clouds, with no significant rainfall forecast. The city of São Paulo will have a minimum temperature of 16°C and a maximum of 20°C. In Rio de Janeiro, temperatures should range between 21°C and 25°C, while Vitória (ES) could reach 28°C.

In the Southern Region, the arrival of drier and colder air masses should favor a decrease in cloud cover as early as Friday. Sunshine should prevail, especially in western Rio Grande do Sul, where the sky may have few clouds at times.

Throughout the afternoon and evening, the rain should cease in western and southwestern Paraná, central and western Santa Catarina, and much of Rio Grande do Sul. Isolated showers are still possible, mainly along the coast.

The formation of the extratropical cyclone over the Atlantic, near the southern coast, is also expected to intensify the winds. There is a yellow warning of potential danger for coastal winds along the entire coastline of Rio Grande do Sul and the coast of Santa Catarina up to the Florianópolis region.

Temperatures will be mild. Curitiba (PR) will have a low of 13°C, while Florianópolis (SC) could reach 22°C. In Porto Alegre (RS), the high should not exceed 20°C.

On Saturday, the weather should remain stable across most of the Southern Region, despite the presence of many clouds in some areas. Northern and northwestern Paraná should have few clouds, while southern and eastern Rio Grande do Sul may experience rain, with the possibility of thunderstorms along the coast.

The yellow warning for coastal winds remains in effect for the coastal strip of Rio Grande do Sul and Santa Catarina. Temperatures are expected to remain low throughout the day. Curitiba will have a minimum of 11°C and a maximum of 20°C. In Porto Alegre, temperatures should range between 13°C and 18°C, while Florianópolis will have a minimum of 15°C and a maximum of 22°C.