Chile, Argentina: Adverse weather forecast across central Chile and western Argentina through at least June 14 /update 1

Thunderstorms are forecast across central Chile and western Argentina through at least June 14. Heavy rainfall, strong winds, and lightning may accompany storms.

As of late June 12, authorities have issued the following weather warnings across the affected area:

• Red rainfall warnings (the highest level on a three-tier scale): Biobio and Nuble regions June 12 and Coquimbo, Metropolitan, O'Higgins, and Valparaiso regions June 13. Up to 8 cm (3 inches) of rainfall is forecast.

• Red wind warnings: Biobio and Nuble regions June 12

• Orange rainfall warnings: Biobio, Coquimbo, Maule, Metropolitan, Nuble, O'Higgins, and Valparaiso regions and Malleco Province in Araucania Region and Huasco Province in Atacama Region June 12-13.

• Orange snowfall warnings: Mountainous areas of Biobio, Coquimbo, Maule, Metropolitan, Nuble, O'Higgins, and Valparaiso regions June 12-13

• Orange wind warnings: Coquimbo, Maule, O'Higgins, and Valparaiso regions June 12-13 and Atacama Region June 13-14.

• Yellow rainfall and wind warnings: Across the rest of the affected area in Chile.

The Argentina National Meteorological Service (SMN) has issued the following weather warnings:

• Orange snow warnings (the middle level on a three-tier scale): Mendoza, western Neuquen, and San Juan provinces.

• Orange wind warnings: Catamarca, western La Rioja, Mendoza, and San Juan provinces.

• Yellow rainfall and wind warnings: Across the rest of the affected area in Argentina.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Authorities in Chile have declared a disaster zone in Biobio Region. Reports indicate one fatality in the Maule Region and one injury in the Nuble Region. Floods have affected more than 1,200 people in the Biobio Region. More than 230 homes in the Biobio Region sustained major damage, and three were destroyed. More than 1,800 homes in Biobio, 68 in Nuble, and 91 in Araucania regions have sustained minor damage. Curanilahue Commune in Biobio Region estimates that around 1,000 homes have been affected by the flooding of the Curanilahue River. Authorities have established six shelters in Arauco, Hualqui, San Rosendo, Los Angeles, Coronel, and Tome communes in the Biobio Region and 13 shelters in Angol, Renaico, Collipulli, Ercilla, Loncoche, and Curarrehue communes in the Araucania Region. Biotren train services through the Biobio railway bridge are suspended due to the increased flow of the Biobio River. More than 53,000 people are without power across central Chile. Classes across central Chile are suspended through at least June 14.

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.

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

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 regional airports. Flooding could block regional rail lines; freight cancellations are possible in areas with heavy rainfall and potential track blockages.

Localized business disruptions could 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.