Switzerland: Adverse weather forecast across much of the country through at least Dec. 23

Severe weather is forecast to occur across much of Switzerland through at least Dec. 23. Heavy snowfall is expected in the Alps over the coming days, with fresh accumulations of 60-120 cm (24-47 inches) possible. At lower altitudes, heavy rainfall is forecast on the central and eastern northern slopes of the Alpes, with rainfall totals of 6-9 cm (2.4-3.5 inches) possible. Strong winds are also expected across much of the country; gusts of 110-170 kph (68-106 mph) are possible in the higher Alpine areas. Heavy downpours may trigger flooding in low-lying areas and landslides on unstable slopes. Strong winds may cause property damage and power outages. Hazardous travel conditions are likely in mountainous regions due to reduced visibility caused by blowing snow.

As of Dec. 21, MeteoSwiss has issued the following weather warnings across the country:

• Red heavy snowfall warnings (the highest level on a three-tier scale): Parts of east-central and eastern Switzerland.

• Orange heavy rainfall warnings: Across parts of central and eastern Switzerland.

• Orange heavy snowfall warnings: Across parts of central, eastern, and southern Switzerland.

• Orange strong wind warnings: Across much of central and eastern and parts of southern Switzerland.

• Yellow heavy rainfall warnings: Across parts of western Switzerland.

• Yellow heavy snowfall warnings: Across parts of southeastern and southern Switzerland.

• Yellow strong wind warnings: Across much of the rest of Switzerland not under orange strong wind warnings.

Officials could update and possibly extend the coverage of weather alerts over the coming day.

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 or a lack of stormwater drainage systems. Sites located 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 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. Disruptions to electricity and telecommunications services are possible where significant winds, 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. 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.

Severe weather could also trigger flight delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.