Storm Triggers Worst Floods in 40 Years in Northwest France

Storm Herminia triggered the worst flooding in four decades in parts of northwest France and created dangerous avalanche conditions in the Alps.

In Brittany, hundreds of people were evacuated from their homes in the department of Ile-et-Vilaine, including the city of Rennes. Further south in Guichen, the Vilaine River rose to a record level, according to Mayor Dominique Delamarre. The flooding disrupted transport and cut power to more than 2,300 homes.

Meteo France issued red alerts for three departments in Brittany, warning people to stay away from rivers, low-lying areas and bridges after back-to-back storms caused waterways to overflow. The most severe flooding is expected along the Vilaine and Seiche rivers, the forecaster said.

Red warnings were also issued along the coasts of northern Spain and Portugal, where the storm could generate waves as high as 14 meters (46 feet).

Herminia has swept in on the heels of Storm Éowyn, which battered Ireland and the U.K. with hurricane-force winds last week. Research suggests climate change could mean fewer winter storms in northwest Europe, but it could increase the intensity of large ones like Éowyn.

Yellow rain alerts are in place for southern England, Wales on Tuesday.

Authorities raised the avalanche risk to level 4 across a large swath of the Swiss Alps, after up to 80 centimeters (32 inches) of fresh snow fell in some areas. That snow is unstable, especially on shady slopes, and could trigger dangerous slides, according to the WSL Institute for Snow and Avalanche Research.

There are also avalanche alerts across much of the French Alps, including an amber warning for the Haute-Alpes department.