The formation of an extratropical cyclone and the advance of a cold front have the potential to alter climatic conditions in Brazil between Wednesday (19) and Thursday (20). This system is gaining strength over the South region, where storms, strong winds, and a sharp drop in temperatures are expected, with lows projected below 10 °C.
In contrast to the cold concentrated in the South, much of the national territory is expected to remain under the influence of heat and atmospheric dryness. The National Institute of Meteorology (Inmet) issued warnings about low air humidity in the Center-West and Southeast, in addition to forecasting isolated storms in western Amazonia and intense rains in the eastern strip of the Northeast.
Detailed forecast by region
The weather should present instability and temperature drops in three states. On Wednesday, rain showers with thunderstorms are expected to begin in Rio Grande do Sul and extend to western Santa Catarina and Paraná. For Thursday, the cyclone off the coast of Rio Grande do Sul and the cold front will reinforce instabilities, generating wind gusts. Minimum temperatures in the interior of Rio Grande do Sul, western Santa Catarina, and southern Paraná are expected to fall to less than 10 °C. In Porto Alegre, the maximum should not exceed 20 °C, while in Curitiba, due to the delayed arrival of cold air, the maximum could reach 28 °C on Thursday.
Sun, heat, and dry weather should continue to dominate most of the area. Inmet warned of the risk of low air humidity in the interior of São Paulo, the Triângulo Mineiro, and southern Minas Gerais. Dry air will also affect the capital of São Paulo during the afternoon. Scattered rain is forecast only on the southern coast of São Paulo and in northeastern Minas Gerais between Wednesday night and Thursday. Early mornings should be cold in the mountain areas and in Minas Gerais, with lows varying between 9 °C and 13 °C, but afternoons may record up to 32 °C in Rio de Janeiro (RJ) and Belo Horizonte (MG).
Air humidity is expected to reach critical levels in Mato Grosso, Goiás, and the Federal District, where there is a danger alert, with very hot afternoons persisting. In Cuiabá (MT), for example, the forecasted maximum is 39 °C on Wednesday and 32 °C on Thursday. An exception occurs in southwestern Mato Grosso do Sul, where the arrival of a cold air mass should cause rain and thunderstorms, reducing the minimum to 14 °C in Ponta Porã (MS) on Thursday. In Brasília, the weather should remain dry, with a minimum of 17 °C in the early morning.
The climate shows a strong dichotomy between the coastal area and the interior. The eastern strip forecasts continuous rain, with a danger alert for intense downpours in northeastern Alagoas and eastern Pernambuco. In contrast, the interior tends to remain sunny and with low humidity. Teresina (PI) should show the greatest thermal variation among capitals, oscillating between 21 °C and 37 °C. In Salvador (BA), rain may moderate the weather, with a maximum of 27 °C, and in the Bahian mountains, early mornings may register cold of up to 11 °C.
Intense heat is a highlight, with temperatures above 40 °C forecast in several municipalities. Maximums of 38 °C were recorded in Palmas (TO) and 37 °C in Manaus (AM) and Porto Velho (RO). Inmet warns of storms accompanied by wind gusts of up to 60 km/h in Acre and western Amazonas. Conversely, stable and dry weather should prevail in southern Pará and Tocantins, regions that are under alert for low air humidity.