Storm "Aurore" swept across parts of northern Europe on Thursday, leaving four dead in Poland and causing substantial damage in Germany, France, the Netherlands and elsewhere.
All four deaths in Poland occurred in the Lower Silesia region.
One person was killed when a van was blown off the road and a builder died when a wall of a house under construction fell over.
In the city of Wroclaw, two died when a tree fell on a passenger car.
The state weather service has issued an alert for strong wind in most of the country.
In the Netherlands, there were reports of mini-tornadoes injuring four people.
Images from the town of Barendrecht near Rotterdam showed damaged roofs, smashed garden sheds and trampolines flipped over in one street.
"You can see that it has been intense," deputy mayor Nico Bults told public broadcaster NOS. "That is quite impressive and of course also frightening for the residents."
A campsite in Zelhem near the German border was also struck by a whirlwind, with a tree branch hitting a chalet, media reports said.
In France, about 40,000 homes were still without power by Thursday evening, with about 4,000 technicians called out to reconnect an initial 250,000 households affected.
Several hundred incidents of disruption were reported on the railways, mostly involving fallen trees blocking tracks.
The strong winds also blew other objects on to the rails, including a trampoline, tarpaulins and sheets of corrugated iron ripped from the roofs of houses, rail operator SNCF said.
Aurore swept east over the country overnight, packing winds of up to 175kph and causing orange weather alerts, the second-highest level, in many parts of the country.
France's Transport Minister Jean-Baptiste Djebbari said in a tweet that the Ile-de-France region around Paris, Normandy in northern France and the eastern Lorraine region had been the worst affected.
Rail traffic was slowly returning to normal on Thursday.
In the western Brittany region, homes were destroyed by flash floods. The storm then travelled on to Germany, where it is called Ignatz, and caused gusts of about 100kph.
About 50,000 households in the east of Germany lost power, mainly in the states of Saxony, Saxony-Anhalt and Thuringia.
Rail travel was suspended in those regions, and disrupted in the rest of the country, rail operator Deutsche Bahn reported, calling on passengers to delay any plans to travel.
People were also urged to avoid walking in forests where they were at risk from falling trees and branches.
In the Czech Republic, the storm left 270,000 homes without electricity and hit transport links as fallen trees blocked roads and rail lines.
At Prague airport, passengers on some planes had to stay on board longer than expected because the wind prevented them from safely using steps.