Chile, Argentina: Adverse weather forecast to continue across southern regions of both countries through at least July 20

Event

Severe weather, including heavy rainfall, snowfall over higher ground, and strong winds, is forecast across southern regions of Chile and Argentina through at least July 20. Daily rainfall totals of 3.5-5 cm (1.4-2 inches) are forecast across parts of Los Lagos Region in Chile and 4-7 cm (1.6-2.8 inches) in western Chubut Province in Argentina. Winds of up to 80 kph (49 mph) are possible in parts of southern Chile and up to 90 kph (56 mph) with gusts of over over 100 kph (62 mph) in parts of southern Argentina.

As of July 19, the Chilean Meteorological Directorate and Argentinian National Meteorological Service (SMN) have issued the following weather warnings:

• Orange heavy precipitation warnings (the middle level on a three-tier scale): Parts of Los Lagos Region in Chile.

• Orange rainfall warnings: Parts of northwestern and western Chubut Province in Argentina.

• Orange strong wind warnings: Parts of central Chubut and eastern, central, and southern Santa Cruz provinces in Argentina.

• Yellow precipitation warnings: Parts of Aysen and Los Lagos regions in Chile.

• Yellow rainfall warnings: Parts of southwestern Chubut, far southwestern Neuquen, and southwestern Rio Negro provinces in Argentina.

• Yellow snowfall warnings: Parts of far eastern Los Lagos Region in Chile; and parts of southwestern Chubut and western Santa Cruz provinces in Argentina.

• Yellow strong wind warnings: Parts of Aysen, Los Lagos, and Magallanes regions in Chile; and parts of eastern and western Chubut, southern Neuquen, southern and central Rio Negro, and western Santa Cruz provinces in Argentina.

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

Hazardous Conditions
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 the 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.

Transport
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 cancelations 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 any floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.

Advice

Monitor local media for weather-related updates and advisories. Confirm all transport reservations and business arrangements before traveling in the affected area. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions throughout the affected areas. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides, as well as mountainous regions where avalanches pose a threat. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Argentina National Meteorological Service (SMN)
Chilean Meteorological Directorate