Brazil: Adverse weather forecast across southeastern regions through at least Jan. 28

Heavy rainfall is forecast across parts of southeastern Brazil through at least Jan. 28. Some coastal parts of the region may receive rainfall accumulations of more than 30 cm (12 inches) through Jan. 28. Thunderstorms and strong winds may accompany the heavy downpours. Sustained heavy rainfall could trigger flooding in low-lying areas and landslides on unstable slopes. Transport disruptions and power outages are also possible in affected areas.

As of early Jan. 25, Brazil's National Institute of Meteorology (Inmet) has issued red (the highest level on a three-tier scale) heavy rainfall warnings for coastal areas of Parana, northern Santa Catarina, and Sao Paulo. Orange heavy rainfall warnings are in place for a slightly wider area along the coasts of Parana, Santa Catarina. and central and southern Sao Paulo. Yellow warnings have been issued across much of the rest of the affected area. Officials could update and possibly 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. In developed areas with easily overwhelmed stormwater drainage systems, additional urban flooding is also possible. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides remain possible in hilly or mountainous areas, especially where heavy rainfall 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.