Switzerland: Adverse weather forecast across southern and central regions through at least April 1

Heavy snowfall, rain, and strong winds are forecast across southern and central Switzerland through at least April 1. MeteoSwiss has issued red snow warnings (the second-highest on a five-tier scale) for far southwestern Grisons, northern Ticino, and eastern Valais cantons. Orange snow warnings are in place for most of the rest of southern Switzerland, and yellow wind and rain warnings are in effect across the rest of the affected area. Officials could update and extend the coverage of weather alerts over the coming days.

The storm system could produce rounds of heavy precipitation (including rain and snow) and strong winds across the affected area. Where precipitation falls as rain, flash and areal flooding is possible. Such flooding may occur in low-lying communities near watercourses and other large bodies of water and in urban areas with easily overwhelmed stormwater drainage systems. Sites downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall. Precipitation could fall as snow in northern parts of the affected area over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in these areas.

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.

The disruptive weather will likely cause delays and cancellations at regional airports. Authorities may temporarily suspend port operations in coastal areas 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 with heavy rainfall and potential track blockages.

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