Rain gives no respite and MetSul warns of “extreme severity” scenario in RS

Holiday Wednesday will not be easy for the people of Rio Grande do Sul. The scenario of heavy rains and storms, which caused damage and deaths this Tuesday, remains at Rio Grande do Sul.

Heavy and torrential showers are expected in several locations, especially in the Northwest, West, Center, South and East of the state.

According to MetSul, the continuation of rain causes the levels of several rivers to increase even more. In Porto Alegre, rain predominates. The predicted minimum is 20ºC and the maximum is 23ºC.

Historical rainfall volumes

Rio Grande do Sul once again experienced the drama of the waters with flooded cities, floods with overflowing rivers, deaths and damage, repeating the scenes from the second half of last year, which marked the height of the El Niño event of 2023-2024 and which was responsible for floods of historic proportions in the State.

The accumulated rainfall in 96 hours until the end of this Tuesday afternoon in several cities in Rio Grande do Sul were extreme and even extraordinary in some municipalities. Cemaden’s rain gauges indicated 448 mm in Segredo, 410 mm in Lagoa Bonita do Sul, 371 mm in Faxinal do Soturno, 329 mm in Santa Maria, 318 mm in Cachoeira do Sul, 313 mm in Candelária and Nova Palma, 312 mm in Arroio do Tigre and 310 mm in Lajeado.

Many cities accumulated between 200 mm and 300 mm from the Center to the east of the State, like almost all of Greater Porto Alegre. In the National Institute of Meteorology network, the volumes in 96 hours until the end of the afternoon totaled 287 mm in Santa Maria, 279 mm in São Gabriel, 271 mm in Bento Gonçalves, 237 mm in Canela, 226 mm in Caçapava do Sul, 215 mm in Rio Pardo, 206 mm in Campo Bom and 203 mm in Porto Alegre.

Extreme severity scenario

And according to MetSul’s prognosis, what is already serious will get worse. “The scenario we see at MetSul Meteorologia, without mincing words, should progress to extremely serious. Several cities must face situations from calamity to disaster”, he warns.

In places where it has already rained 200 mm to 400 mm, data from numerical models indicate another 150 mm to 300 mm or more by Saturday, which would mean that in just one week the accumulation in part of the State will be between 500 and 700 mmmuch more than it rains all autumn, on average.

A cold front will advance through Rio Grande do Sul this Wednesday and Thursday, reinforcing the rain in several regions with periods of torrential rain and high volumes in a short interval, which could generate flash floods. There is also a risk of isolated hailstorms and gales. Models differ, but at the end of the week, there is a risk of another rain event due to an area of low pressurewhich would make the situation even worse.