Chile, Argentina: Adverse weather forecast across parts of eastern Chile and western Argentina through at least Nov. 2

Severe weather is forecast across parts of eastern Chile and western Argentina through at least Nov. 2. A combination of thunderstorms, heavy rainfall, and strong winds are forecast across parts of the affected area, as well as snowfall over elevated areas. Heavy downpours may trigger flooding in low-lying areas, and strong winds could cause property damage and power outages. Transport disruptions are likely in the region due to adverse weather, especially in mountainous areas due to icy roads and reduced visibility caused by blowing snow. Authorities have closed the Los Libertadores/Cristo Redentor Pass between Mendoza Province in Argentina and Valparaiso Region in Chile as of early Nov. 1 due to adverse weather conditions.

As of early Nov. 1, the Chilean Meteorological Directorate and Argentinian National Meteorological Service (SMN) have issued the following weather warnings:

• Orange heavy rainfall warnings (the middle level on a three-tier scale): Parts of central and eastern Neuquen Province in Argentina.

• Orange strong winds warnings: Parts of western Antofagasta and western Atacama regions in Chile.

• Yellow heavy rainfall warnings: Parts of eastern and southern Mendoza, central Rio Negro, and eastern and southern San Luis provinces in Argentina.

• Yellow thunderstorm warnings: Parts of southern and western Cordoba, southern La Rioja, and northern and western San Luis provinces in Argentina and parts of eastern Biobio, central and eastern La Araucania, eastern Maule, eastern Metropolitana, eastern Nuble, eastern O'Higgins, and eastern Valparaiso regions in Chile.

• Yellow snowfall warnings: Parts of western Neuquen and southwestern Rio Negro provinces in Argentina.

• Yellow strong wind warnings: Across much of San Luis Province in Argentina and parts of central Atacama Region in Chile.

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

The storms could produce rounds of heavy precipitation (including rain and snow), strong winds, and isolated thunderstorm activity across parts of the affected area. Where precipitation falls as rain, flash, and areal flooding is possible. Such flooding is possible in low-lying communities near watercourses and other large bodies of water, as well as in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs 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; 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. 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 any floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.