Europe: Adverse weather forecast across southern and central regions through at least Dec. 26

Severe weather is forecast across parts of southern and central Europe through at least Dec. 26. A storm system is expected to bring strong winds, heavy rainfall, and snowfall to mountainous areas in Albania, Bosnia and Herzegovina, Croatia, southern and eastern France, southern Germany, Greece, Italy, Kosovo, Montenegro, Serbia, Slovenia, eastern Spain, and Switzerland over the coming days.

The respective meteorological services have issued the following weather warnings across the affected area:

• Red strong wind warnings (the highest level on a three-tier scale): Coastal waters in Croatia.

• Orange heavy rainfall warnings: Southeastern France and western Greece.

• Orange heavy snowfall warnings: Western Austria, northern Bosnia and Herzegovina, northern Croatia, eastern France, southern Germany, western Serbia, western Slovenia, eastern Spain, and central and southwestern Switzerland.

• Orange strong wind warnings: Southern Bosnia and Herzegovina, northern and southern Croatia, most of Italy, eastern Spain

• Yellow heavy rainfall, snowfall/ice, and strong wind warnings: The rest of the affected area.

Officials will likely update and extend the coverage of weather alerts 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 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, and decreased visibility is likely in mountainous areas. Rain-induced landslides may occur in areas of elevated terrain, and avalanches are possible 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 or snow could block regional rail lines; freight and passenger train delays and cancellations are likely in areas with heavy rainfall and potential track inundation.