The Swiss ski resort of Zermatt was cut off and tourists and residents were told to stay indoors in the French resort of Tignes because of heavy snow in the Alps on Thursday.
Tignes Mayor Serge Revial said there was a high risk of avalanches and “we had to make a decision to protect people”, after more than a metre of snow was dumped over the town.
Although snow is not uncommon in the Alps in April, the disruption left thousands of homes in the Savoie region of eastern France without power.
In neighbouring Switzerland, the Simplon Pass into Italy and the Great St Bernard Tunnel were closed to traffic, while two cantons were badly affected.
In Valais and Bernese Oberland, tourists heading for ski holidays were hit by the disruption.
Road and rail routes were cut off into the resort of Zermatt in the southern canton of Valais; power was cut throughout Thursday and mobile phone networks were badly disrupted.
Queues built up outside the only supermarket open in the town, according to Swiss media.
The Alertswiss app warned of the risk of avalanches and falling trees in Valais as well as major disruption to transport. Schools were closed for the day in the city of Sion.
People travelling to the area for Easter were advised to delay their trips until Saturday. Local police urged people to stay at home if possible.
South of Zermatt, power outages were reported in 37 of the 74 municipalities in the Aosta Valley in north-west Italy, and a bridge collapsed in Biella in nearby Piedmont.
The biggest problem in north-west Italy was heavy rain, as rivers burst their banks and a 92-year-old man was thought to have drowned because of flooding in his home at Monteu da Po near Turin.
A torrent of water cascaded through the streets of the village, in hills close to the River Po.
Red alerts were issued in several valleys, but the biggest concern was for the Po where river levels were expected to peak in the next 24 hours.
Meteorologists said in some areas more than 20cm of rain had fallen in 36 hours, and extreme peaks had been recorded of even higher levels.
“It’s been raining non-stop for days, very, very hard, although it’s stopped now,” Manuela, a 33-year-old Turin resident, told the BBC.
“Two rivers, the Po and the Dora, near Turin have burst their banks. The city is fine but they had to shut several bars and restaurants by the river in Turin.”
