Road were blocked and thousands of people were left without power in southern and central Europe, as rains and violent winds sparked flooding and tore trees from their roots.
Thick snow has also cloaked French and Italian mountain regions, trapping hundreds of drivers in their cars and tourists in hotels.
In Italy, where Venice was inundated by near-record flooding and ferocious storms drove high winds reaching up to 180 kilometres an hour, authorities announced a further six deaths, after confirming five people had died on Monday.
"We are facing one of the most complex meteorological situations of the past 50 to 60 years," said Angelo Borrelli, head of the national civil protection agency.
Luxury yachts lay smashed in the harbour of Rapallo near Genoa after a dam broke under pressure.
"It was like a tsunami," one stunned port worker was quoted as saying by Italian media.
"We thought the danger would come from the mountains, we thought the problem would be landslides," said Liguria head Giovanni Toti.
"Instead, we get a coastal storm surge the likes of which we’ve never seen," he said.
Authorities Tuesday reported a woman died when her home was engulfed by a mudslide in the northern region of Trentino, a man was killed in the northeastern Veneto region by a falling tree, and a firefighter died during relief operations in South Tyrol.
Elsewhere, a man was killed while kitesurfing on Monday near the town of Cattolica on the Adriatic coast, while the body of another man was recovered Tuesday in Lake Levico in the north.
A man was also missing at sea off Calabria in the southwest, while the body of another was found in a stream in northern Italy.
Italian media reported that around 170 people, tourists and hotel staff, were stranded by heavy snowfall at the Stelvio Pass on the Swiss border.
Meanwhile in Friuli Venezia Giulia, local authorities said some 23,000 people were without power.
In France, more than 1,000 drivers were trapped in their cars for the night in the mountains of the Massif Central region as the roads were engulfed in snowstorms.
Another 400 had to spend the night in train carriages at the main station in the eastern city of Lyon after heavy snow blocked the tracks.
About 60,000 homes still remained without power on Tuesday evening across France -- mostly in the east and centre.
Another 21,000 homes were also cut off on the Mediterranean island of Corsica, which was placed on red alert Monday for powerful winds, shutting its airports and ports.
Croatia’s Adriatic coast has also been battered by gale-force winds and heavy rains that have flooded streets, cut off power and ensnared road and maritime traffic.
Meanwhile, a Slovenian surfer who went missing on Monday in the sea off Croatia’s northern Istria peninsula was rescued Tuesday after being swept south to the Italian bay of Trieste.
In Spain, over 100 soldiers were helping electrical repair crews to reach isolated areas of the northern region of Asturias, blanketed by heavy snowfall at the weekend.
Italy’s canal city of Venice was swamped as heavy rainfall pushed the water levels to near record levels on Monday.
Tourists were barred from St Mark’s Square as local authorities said the "acqua alta" (high water) peaked at 156 centimetres. The waters have only topped 150 centimetres five times before in recorded history.
Art experts were racing to evaluate the damage to thousand-year old mosaics in St Mark’s Basilica after the Bapistry and Zen Chapel flooded.
Two paintings by Spanish artist Joan Miro were damaged at the Palazzo Zaguri, where they had been waiting to be hung.
Meteorologists expect the harsh weather to gradually ease in Italy.
Storms have also swept into Switzerland, buffeting the Ticino region near the Italian border overnight, according to public broadcaster RTS.
Roads were blocked by fallen trees and flooding, while strong winds ripped roof sections off buildings, including in Giubiasco where police said part of a firm’s roof had smashed into a moving train and a house, without causing injury.
In southern Austria, authorities have deployed hundreds of mobile anti-flooding dams as rivers burst their banks, while in the city of Salzburg a roof section from the mediaeval ramparts flew off in high winds.
An 80-year-old driver and his passenger, 76, were killed Tuesday in an accident caused by a landslide on a road near Maribor in Slovenia. — AFP/VNS.