Portugal, Spain: Adverse weather forecast across parts of northern Portugal and northwestern Spain through at least Sept. 26

Adverse weather is forecast across northern Portugal and northwestern Spain through at least Sept. 26. Heavy rainfall and strong winds are expected across the region over the coming days, with total rainfall accumulations of 10-20 cm (4-8 inches) and winds gusting up to 90 kph (56 mph) possible in parts of the affected area through Sept. 26. Heavy downpours may trigger flooding in low-lying areas and strong winds may cause property damage and power outages.

The Portuguese Institute of the Sea and Atmosphere (IPMA) has issued yellow heavy rainfall warnings (the lowest level on a three-tier scale) across Aveiro, Braga, Porto, Viana do Castelo, Vila Real and Viseu districts Sept. 24 and orange rainfall warnings across these districts Sept. 25-26. Yellow rainfall warnings have also been issued for Coimbra District Sept. 25-26 and Braganca and Guarda districts Sept. 26. Yellow strong wind warnings are in place for Braganca, Guarda, Vila Real, and Viseu districts Sept. 25-26 and Braga and Viana do Castelo districts Sept. 25.

The Spanish State Meteorological Agency (AEMET) has issued orange rainfall warnings across eastern and south-central parts of Galicia Autonomous Community Sept. 25-26 and yellow heavy rainfall warnings across much of the rest of Galicia Sept. 25-26 and parts of western Asturia and northwestern Castile and Leon autonomous communities Sept. 25. Yellow strong wind warnings are also in place across much of the affected areas Sept. 25-26.

Officials could update and extend the coverage of weather alerts as conditions change over the coming days.

Sustained heavy rainfall could trigger additional 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.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around 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. Disruptive weather may cause delays and cancellations at airports in the affected regions. Flooding could block regional rail lines; freight cancellations are possible in areas with heavy rainfall and potential track blockages.

Localized business disruptions may occur in areas impacted by severe weather; some businesses might not operate at full capacity because of damage to facilities, possible evacuations, and some employees' inability to reach work sites.