Brazil's National Institute of Meteorology (Inmet) placed parts of Paraná, Santa Catarina and Rio Grande do Sul under a red alert, its highest danger level, for this Saturday (24), the day before the second round of the presidential election. An extratropical cyclone forming off the southern coast is expected to bring more than 100 millimeters of rain, wind gusts above 100 km/h and hail, according to the institute.
In Santa Catarina, the red warning covers the North, the Serra, the Itajaí Valley and the West. In Paraná, it applies to the Southwest, Southeast, West, Center-South and Center-East regions. In Rio Grande do Sul, the highest-risk area is the state's Northwest. Around those zones, Inmet has issued an orange alert for other parts of the three states and a yellow warning for the rest of the region. According to ND Mais, 273 of Santa Catarina's 295 municipalities are under the orange alert, and the entire state is covered by some level of warning.
The event results from the combined action of the cyclone, organizing over the southwestern South Atlantic, a cold front positioned between Rio Grande do Sul and Santa Catarina, and low-pressure areas between northern Argentina, Paraguay and southern Bolivia, according to Inmet. In the orange-alert areas of Santa Catarina, the forecast calls for 30 to 60 millimeters of rain per hour or up to 100 millimeters over the day, with gusts between 60 km/h and 100 km/h.
Rain on election Sunday
On Sunday (25), when polling stations operate from 8 a.m. to 5 p.m., heavy rain is expected to continue in Paraná, with thunderstorms throughout the day, and during the early hours in Santa Catarina, mainly on the coast and in the Itajaí Valley, according to the private forecaster Climatempo. In Rio Grande do Sul, rain should be lighter and passing, as a colder, drier air mass moves in and pushes temperatures down: Florianópolis should range from 15°C to 19°C, Curitiba from 11°C to 20°C and Porto Alegre from 15°C to 18°C. "We expect heavy rain, with lightning and strong winds," Climatempo meteorologist César Soares told G1. The company projects gusts of up to 90 km/h on Saturday in the region, while Inmet estimates winds above 100 km/h in the red-alert areas.
Risks and guidance
According to Inmet, the conditions may cause power outages, falling trees, flooding and crop damage across the three states. Civil Defense and the institute advise residents not to shelter under trees during gusts, to avoid parking near transmission towers and billboards, and to unplug electrical appliances during storms. In an emergency, Civil Defense can be reached at 199 and the Military Fire Department at 193.
Brazil's South has faced a string of extreme weather events in recent years, including the historic flood that hit Rio Grande do Sul in May 2024. Reports by the Intergovernmental Panel on Climate Change (IPCC) indicate that global warming increases the intensity of extreme rainfall in South America. Faced with this pattern, Inmet and state civil defense agencies have been issuing alerts earlier and earlier, as they did this weekend, to give residents time to protect themselves.