Brazil: Red weather warnings issued for several southern regions Dec. 7

Brazil's National Institute of Meteorology (INMET) has issued red weather warnings (the highest level on a three-tier scale) for parts of northern Rio Grande do Sul, southern Parana, and central and western Santa Catarina on Dec. 7. Various other orange and yellow warnings have been issued for surrounding regions. The red warning is in place through 23:59 Dec. 7. INMET has warned of a high risk of major flooding, river overflows, and major landslides. Officials could update and extend the coverage of the relevant weather alerts over the coming days.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil. Power outages and disruptions to telecommunications services are likely where significant flooding, landslides, or strong winds impact utility networks.

Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel in affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather could also trigger intermittent flight delays and cancellations at airports in the affected regions, though these are unlikely to be severe or prolonged. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas with heavy rainfall and track inundation. Localized business disruptions may occur in low-lying areas.