Inmet: weather forecast for Thursday (October 1st) and Friday (October 2nd)

October begins with the passage of a cold front, associated with an extratropical cyclone in the Atlantic Ocean, off the coast of the South and Southeast regions of Brazil. According to the National Institute of Meteorology (Inmet), these systems maintain unstable weather, with rain, thunderstorms, and the possibility of hail in areas of the Central-West and Southeast. In the South, the arrival of a high-pressure system, also called an anticyclone, favors a decrease in cloud cover and a drop in temperatures.

Throughout Friday (October 2nd), the anticyclone will gradually move towards the Atlantic and, with the counter-clockwise wind circulation around its center, will contribute to transporting cold and humid air from the ocean to the eastern part of the Southeast region. As a result, the cold should intensify in São Paulo and temperatures will generally drop across much of this region.

Another highlight is the advance of instability over the interior of Brazil towards Matopiba (the agricultural region between the states of Maranhão, Tocantins, Piauí, and Bahia), after a week marked by low air humidity levels, especially in western Bahia. Rain with isolated thunderstorms is forecast in areas of Bahia, as well as southern Maranhão and Piauí. On the other hand, the weather remains hot and dry in Amapá, northeastern Pará, and the interior of the Northeast. Follow the forecast by region:

Northern Region

Thursday (October 1st): October begins with two distinct situations over Northern Brazil. In the western region, encompassing Acre, Rondônia, and Amazonas, the first day of the month will see showers accompanied by isolated thunderstorms. Isolated rain is also expected in Roraima and southwestern Pará. For Acre, Rondônia, Roraima, and Amazonas, there is a yellow warning indicating potential danger for storms. There is also a possibility of isolated rain in parts of western and northwestern Pará and southwestern Tocantins.

Meanwhile, in the eastern part of the region, between Amapá, the remaining areas of Pará and Tocantins, the day will be sunny with varying cloud cover throughout. For southeastern Tocantins, there is a yellow warning of potential danger due to low air humidity. The day will be hot in the region. The minimum temperature among the capitals will be 23°C in Rio Branco (AC) and Porto Velho (RO). In Roraima, temperatures will be very high from early morning. The minimum in Boa Vista (RR) will be 28°C, and the maximum will reach 37°C. Palmas remains the hottest capital in the North region, with temperatures between 25°C and 39°C.

Friday (2/10): The week ends with unstable weather across much of the North region, except in Amapá and the coast of Pará, where the day will be mostly cloudy but without rain. On the other hand, in Acre, Amazonas, Rondônia and Roraima, as well as western and southern Pará and central and southern Tocantins, including the capital Palmas (TO), there will be showers with isolated thunderstorms.

Isolated showers are also occurring in central Pará and northern Tocantins. There is a possibility of isolated rain in northwestern Pará. Temperatures in the capital cities range from a low of 23°C in Rio Branco (AC) to a high of 36°C in Boa Vista (RR). In Palmas (TO), Rio Branco (AC), Manaus (AM), and Belém (PA), temperatures will reach 35°C.

North East Region

Thursday (October 1st): October begins with sunshine in the Northeast region, and no rain is forecast for the area. In the morning, the sky will be clear and cloudless in western Bahia and southern Piauí, while other areas will have few clouds. Throughout the day, the sky will become cloudy in Maranhão, Piauí, northern and eastern Ceará and Rio Grande do Norte, and in the eastern part of the region, but will remain predominantly cloudy in central and western Bahia, southwestern Ceará, and western Pernambuco.

For eastern Maranhão, much of Piauí, central and southern Ceará, western Rio Grande do Norte, Paraíba, Pernambuco, Alagoas and Sergipe, as well as northern, central and western Bahia, there is a yellow warning of potential danger due to low air humidity. The minimum temperature in the capitals will be 21°C in Maceió (AL) and the maximum 39°C in Teresina (PI).

Friday (2/10): Areas of instability forming over the interior of Brazil are affecting the Northeast region, bringing rain accompanied by isolated thunderstorms to southern Maranhão and western and southern Bahia. For these areas, there is a yellow warning for potential storm danger. Isolated showers are also occurring in western Piauí.

Along the coastal strip, the sky will be mostly cloudy with a possibility of isolated showers on the coast of the states of Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe, and Bahia. The weather will be sunny with few clouds between central Maranhão and Piauí, central and southern Ceará, southwestern Rio Grande do Norte, western Paraíba and Pernambuco, and northern Bahia. In Recife (PE) and Maceió (AL), the minimum temperature will be 23°C. The maximum will be 39°C in Teresina (PI). In the other capitals, the maximum temperature will vary between 29°C and 32°C.

Midwest region

Thursday (October 1st): The weather will be unstable on the first day of October in the Central-West region. Rain with thunderstorms is expected in Mato Grosso do Sul, southern and western Goiás, and eastern, southern, western, and northwestern Mato Grosso. There is a possibility of hail in the Central-West, especially in Mato Grosso do Sul during the morning. Therefore, an orange warning for dangerous storms is in effect between southwestern and southern Mato Grosso and Goiás, and northwestern, northern, and northeastern Mato Grosso do Sul.

There is also a yellow warning of potential danger for storms in the northwest, west, central and east of Mato Grosso, in central Goiás, in the Federal District and in the remaining areas of Mato Grosso do Sul.

In southern Mato Grosso do Sul, the rain decreases throughout the day and, by nightfall, the weather becomes more stable, with many clouds. No rain is forecast only for northeastern Goiás, in the region of the Chapada dos Veadeiros National Park, where the sky will be mostly cloudy.

For northeastern Goiás, the Federal District, and eastern Goiás, there is a yellow warning of potential danger due to low air humidity. In Brasília (DF) and Goiânia (GO), Thursday will be another very hot day, with temperatures between 21°C and 35°C in both capitals. In Cuiabá (MT), the rain will bring the maximum temperature to 30°C. The day will be mild in Mato Grosso do Sul. In Campo Grande (MS), the temperature will be between 19°C and 26°C.

Friday (2/10): Rainfall is intensifying over the Central-West region. In Mato Grosso, Goiás, the Federal District, and the northwest, north, and northeast of Mato Grosso do Sul, there are isolated thunderstorms. There is a yellow warning for potential storm danger in almost the entire region. Only the south of Mato Grosso do Sul is outside the warning area.

With the rain, temperatures are starting to drop slightly in all capital cities, relieving the intense heat that has been felt throughout the week. The minimum temperature will be 19°C in Campo Grande (MS), where the maximum should not exceed 25°C. In Cuiabá (MT), the maximum will be 28°C, and in Brasília (DF) and Goiânia (GO), 30°C.

Southeast

Thursday (October 1st): October begins with sunny and warm weather across much of the Southeast region, but the passage of a cold front will rapidly change weather conditions over much of the region throughout the day. As a result, rain with thunderstorms is expected in the morning in western and southern São Paulo. There is a possibility of hail.

During the afternoon and evening, rain will reach southern Minas Gerais, Rio de Janeiro, and central and southern Espírito Santo. The weather will be quite unstable, with conditions favorable for rain and thunderstorms in the Triângulo Mineiro region, southern Minas Gerais, Rio de Janeiro, and São Paulo. The chances of hail remain and may affect various points in these areas throughout the day, especially in Rio de Janeiro and southeastern Minas Gerais.

For the Triângulo Mineiro region, southern Minas Gerais, central and southern Rio de Janeiro, and northwestern, northern, and eastern São Paulo, there is an orange warning for dangerous storms. The capitals São Paulo (SP) and Rio de Janeiro (RJ) are within this warning area. For the remaining areas of São Paulo and Rio de Janeiro, southern Espírito Santo, and central and eastern Minas Gerais, there is a yellow warning for potentially dangerous storms, including the capital Belo Horizonte (MG).

On the other hand, in northern Minas Gerais and Espírito Santo, the day will be sunny, with few clouds and intense heat. There is a yellow warning of potential danger due to low air humidity in the northwest, north, center and east of Minas Gerais, including Belo Horizonte (MG) and Juiz de Fora (MG).

Before the rain, the capital of Minas Gerais will have another very hot day. The high will reach 37°C in Belo Horizonte (MG). The heat will also arrive in Vitória (ES), with a high of 35°C. On the other hand, the passage of the cold front through São Paulo (SP) will cause the temperature to drop considerably. In the capital of São Paulo, the low will be 16°C, the lowest among the capitals, and the high should not exceed 20°C.

Friday (2/10): The rains continue and are affecting northern Minas Gerais. Isolated thunderstorms are expected throughout the states of Minas Gerais, Espírito Santo, and Rio de Janeiro, as well as northwestern and northern São Paulo. A yellow warning for potential storm danger is in effect for Minas Gerais, Espírito Santo, northern Rio de Janeiro, and northwestern and northern São Paulo. Isolated showers are expected in other areas of São Paulo. The passage of a cold front through Rio de Janeiro (RJ) is causing temperatures to drop in the capital, with a minimum of 20°C and a maximum of only 24°C. The cold intensifies in São Paulo (SP), with a minimum of 13°C and a maximum of 16°C. The heat decreases in Minas Gerais, but the maximum temperature still reaches 31°C in Belo Horizonte (MG).

South

Thursday (October 1st): It is still raining, but the clouds are decreasing throughout the day in the Southern Region. In the morning, there is rain with thunderstorms in Paraná and Santa Catarina. There is a risk of hail in northwestern Paraná. For northwestern, northern, and eastern Paraná, there is a yellow warning of potential danger for storms. In Rio Grande do Sul, the clouds are decreasing, but there is still a possibility of isolated showers in the northwest and north of the state.

During the afternoon, the sky will be mostly cloudy with isolated showers in northern and eastern Paraná. There is a possibility of isolated showers in eastern Santa Catarina and southern Rio Grande do Sul. In western, southwestern, and southern Paraná, and in the remaining areas of Santa Catarina and Rio Grande do Sul, there is no longer a chance of rain. During the night, the sky will be mostly clear and very cold in Rio Grande do Sul and Santa Catarina.

Cloud cover persists over Paraná, but there is only a possibility of isolated rain in the north and east of the state. In the capital cities, the minimum temperature will be 13°C in Porto Alegre (RS) and Curitiba (PR), and the maximum will reach 23°C in Porto Alegre (RS). The day will be cold in Florianópolis (SC), where the maximum temperature will not exceed 16°C.

Friday (2/10): Low temperatures in the Southern Region. In Rio Grande do Sul, the sky will be mostly clear throughout the day. In Santa Catarina and Paraná, the sky will be mostly cloudy with a possibility of isolated rain in the northwest, north, and east of Paraná and along the coastal strip of Santa Catarina. The early morning will be cold, with temperatures that may reach around 5°C in mountainous regions of Santa Catarina and Rio Grande do Sul and on the border between Rio Grande do Sul and Uruguay.

In the capital cities, the minimum temperature will be 10°C in Porto Alegre (RS), where the maximum reaches 21°C. In Curitiba (PR) and Florianópolis (SC), the cold persists throughout the day, and the maximum temperatures do not exceed 17°C and 18°C, respectively.