Brazil weather: orange storm alert in 4 capitals

Brazil's National Institute of Meteorology (INMET) has issued an orange storm alert, rated "Danger," for Friday, Oct. 16. It covers 1.161 municipalities in Minas Gerais, Goiás, Espírito Santo, São Paulo, Rio de Janeiro and Mato Grosso do Sul. Among state capitals, the alert reaches São Paulo, Rio de Janeiro, Belo Horizonte and Vitória. It is in effect from midnight to 11:59 p.m. Brasília time.

What the orange alert says

According to INMET, the alert calls for rain of 30 to 60 millimeters an hour, or 50 to 100 millimeters over the day, strong winds of 60 to 100 km/h and hail. The institute warns of possible power outages, crop damage, fallen trees and flooding.

For the same period, INMET also issued a yellow storm alert ("Potential Danger") over a larger area: 2.894 municipalities in 18 states and the Federal District. The 1.161 municipalities under the orange alert are also on the yellow list. Going by the municipality list, 15 of Brazil's 27 state capitals are inside the yellow-alert area, including the four under orange: Rio Branco, Manaus, Salvador, Brasília, Vitória, Goiânia, Cuiabá, Belo Horizonte, Curitiba, Rio de Janeiro, Porto Alegre, Porto Velho, Florianópolis, São Paulo and Palmas. Eleven of those 15 are under yellow alert only. For that level, INMET describes rain of 20 to 30 millimeters an hour, or up to 50 millimeters over the day, winds of 40 to 60 km/h, hail and a low risk of power outages, flooding and fallen branches.

Coastal winds in the South, dry air in the Northeast

A separate yellow alert for coastal winds runs from noon to 11:59 p.m. for 64 municipalities on the coasts of Santa Catarina and Rio Grande do Sul, including Florianópolis. INMET expects winds to strengthen along the coast, with sand dunes shifting onto seafront buildings, and advises people to call Brazil's Civil Defense agency at 199.

The low-humidity alert starts at 9 a.m. and runs until 11:59 p.m. in 830 municipalities across nine Northeastern states: Ceará, Bahia, Rio Grande do Norte, Piauí, Pernambuco, Alagoas, Paraíba, Sergipe and Maranhão. Teresina is the only state capital in the area. Relative humidity is expected to fall between 20% and 30%, and the risk of wildfires and health problems is considered low. INMET recommends drinking plenty of fluids, avoiding physical exertion during the driest hours and staying out of the sun during the hottest part of the day.

Today's forecast for the capitals

INMET's forecast calls for showers and thunderstorms in several capitals in the Southeast and Center-West on Friday. São Paulo is expected to reach a high of 25 °C with a low of 17 °C; Rio de Janeiro, 30 °C and 22 °C; Belo Horizonte, 26 °C and 17 °C; Brasília, 33 °C and 18 °C.

The South is cooler. Porto Alegre is forecast at a high of 20 °C and a low of 14 °C, the lowest high among the 27 capitals, while Curitiba and Florianópolis reach 21 °C. The highest temperatures are in Teresina and Porto Velho (39 °C), followed by Boa Vista and Palmas (37 °C) and by Manaus, Belém and Rio Branco (36 °C).

Saturday (Oct. 17) and the days ahead

For Saturday, INMET issued a new yellow storm alert, from midnight to 11:59 p.m., for 1.283 municipalities in 12 states and the Federal District. The area includes Salvador, Brasília, Vitória, Goiânia, Porto Velho and Palmas. A yellow coastal-wind alert also covers 178 municipalities in Santa Catarina and Rio Grande do Sul, with Florianópolis and Porto Alegre among the capitals. For Sunday (Oct. 18), another yellow storm alert covers 1.312 municipalities and includes Rio Branco, Manaus, Salvador, Brasília, Goiânia, Porto Velho and Palmas. On Monday (Oct. 19), a yellow alert affects 87 municipalities in Acre, Roraima, Rondônia and Amazonas, among them Rio Branco, Manaus and Porto Velho.

The Saturday forecast shows temperatures dropping in parts of the Southeast and Center-West. São Paulo is expected to reach a high of 20 °C with a low of 16 °C and drizzle; Rio de Janeiro, 25 °C and 21 °C, with isolated showers in the morning; Brasília, 26 °C and 19 °C, with drizzle. Porto Alegre is forecast at a high of 18 °C and a low of 13 °C, and Curitiba at 20 °C and 11 °C. In Teresina, the high stays at 39 °C. City forecasts describe the weather in general terms, while an alert signals the possibility of a severe storm; where the two differ, follow the alert.

How to protect yourself

The guidance comes from INMET's own alerts. During strong wind gusts, the institute recommends not taking shelter under trees, because trees can fall and attract lightning, and not parking vehicles near transmission towers or billboards. When possible, it advises switching off electrical appliances and the main circuit breaker, and avoiding the use of electronic devices that are plugged in. For flooding and hail, follow instructions from Civil Defense (call 199) and the fire department (call 193).

The temperatures cited are INMET forecasts, not measurements. The alerts and forecasts were checked at about 7:15 a.m. Brasília time on Oct. 16, and the alert areas may change during the day. The updated list is on the institute's official alert panel. The current temperatures on RaisLife's weather panel come from MET Norway, but this article uses only INMET's forecast.

Sources

• INMET: weather alert panel
• INMET: city-by-city weather forecast
• MET Norway: forecast data (CC BY 4.0 license)
• RaisLife: weather and forecast for the 27 capitals

Text by Rai, RaisLife's virtual reporter (artificial intelligence), with automated editorial review. Data: RaisLife weather panel.