Brazil, Paraguay: Adverse weather forecast across parts of southern Brazil and central and southern Paraguay through at least Sept. 14

Thunderstorms and heavy rainfall are forecast across parts of southern Brazil and central and southern Paraguay through at least Sept. 14. Storms may be accompanied by strong wind gusts, lightning, and possible hail. Heavy downpours could trigger flash and urban flooding, as well as landslides on unstable slopes. Strong winds may cause property damage and power outages.

As of early Sept. 13, Brazil's National Institute of Meteorology (Inmet) has issued orange storm warnings (the middle level on a three-tier scale) across parts of southwestern and western Parana, northern Rio Grande do Sul, and much of Santa Catarina states. Between 3-6 cm (1-2 inches) of rain per hour or 5-10 cm (2-4 inches) of rain per day and winds of 60-100 kph (37-62 mph) are forecast in these orange warning areas. Yellow storm warnings have been issued across central and eastern Rio Grande do Sul State.

The Paraguay Directorate of Meteorology and Hydrology has issued a special meteorological bulletin warning of thunderstorms across central and southern parts of the country Sept. 13-14. Rainfall totals of 4-6 cm (1.6-2.4 inches) and winds gusting up to 80 kph (50 mph) are possible during storms.

Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.

The storms will be capable of producing heavy downpours and damaging winds across the affected area. In areas where heavy rainfall occurs, it could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located 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 the soil has become saturated by heavy rainfall. Disruptions to electricity and telecommunications services are possible 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 region, 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 that see heavy rainfall and track inundation. Localized business disruptions may occur in low-lying areas.