Chile, Argentina: Adverse weather forecast across parts of Chile and Argentina through at least June 18

Severe weather is forecast across much of central Chile and parts of southern and western Argentina through at least June 18. Heavy rainfall is forecast across the region, with precipitation likely falling as snow in Andean areas.

The Meteorological Directorate of Chile has issued the following weather warnings across the affected area June 17-18:

• Orange heavy rainfall warnings (the middle level on a three-tier scale): Arauco Province in Biobio Region.

• Orange strong wind warnings: Much of Biobio and parts of western Nuble regions.

• Yellow rainfall warnings: Coastal and lower elevated inland areas of Biobio, La Araucania, Los Rios, Maule. Metropolitan, Nuble, O'Higgins, and Valparaiso regions.

• Yellow snowfall warnings: Mountainous areas of Biobio, La Araucania, Los Rios, Maule. Metropolitan, Nuble, O'Higgins, and Valparaiso regions.

• Yellow strong wind warnings: Across much of the affected area.

The Argentina National Meteorological Service (SMN) has issued the following weather warnings across the affected area June 17:

• Orange snow warnings (the middle level on a three-tier scale): Parts of western Neuquen Province.

• Yellow heavy rainfall warnings: Coastal areas of southeastern Chubut and eastern and northeastern Santa Cruz provinces.

• Yellow snowfall warnings: Across much of Santa Cruz and parts of western Chubut, western Mendoza, and southwestern Rio Negro provinces.

• Yellow strong wind warnings: Parts of southern and western Mendoza and central, northern, and western Neuquen provinces.

The SMN has issued further orange and yellow weather warnings across parts of the affected area June 18. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change 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.

Precipitation could fall as snow in higher elevations over the coming days. Wind gusts could cause blowing and drifting snow, and decreased visibility is likely in mountainous areas. Rain-induced landslides cannot be discounted in areas of elevated terrain. There is also the possibility of avalanches in mountainous areas where the snowpack has become unstable due to heavy snowfall. Power outages could occur throughout the affected area.

Floodwaters and related debris may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around the affected area. Flooding in urban areas could also result in significant traffic congestion. Heavy snow will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations. Mountain passes, and tunnels could be closed as a precautionary measure during periods of intense snowfall.

The disruptive weather will likely cause some delays and cancellations at airports in affected areas. Authorities may temporarily suspend port operations if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding or snow could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding or avalanches, could persist well after conditions have improved—it could take days before floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.