Record-breaking rain has produced floods in a vast swathe of Italy's Tuscany region as Storm Ciaran pushed into the country, trapping residents in their homes, inundating hospitals and overturning cars.
At least five people were killed, bringing the storm's death toll in western Europe to 12 on Friday.
Italian Civil Protection authorities said 200 millimetres of rain fell in a three-hour period, from the city of Livorno on the coast to the inland valley of Mugello, and caused riverbanks to overflow.
Video shows at least a dozen cars getting pushed down a flooded road.
"There was a wave of water bombs without precedence," Tuscany Governor Eugenio Giani told Italian news channel Sky TG24 as he tried to describe the downpour.
The dead in Tuscany included an 85-year-old man found in the flooded ground floor of his home near the city of Prato, north of Florence, and an 84-woman who died while trying to push water out of her home in the same area, according to Italian news agency ANSA.
Another victim was reported in Livorno.
At least three people were missing Friday in Tuscany, and one person was reported missing in the mountains of Veneto, north of Venice.
Other regions were on high alert and authorities warned that the storm was heading towards southern Italy.
Ciaran left at least seven people dead as it swept across the United Kingdom, Spain, France, Belgium, the Netherlands and Germany on Thursday.
The storm devastated homes, caused travel mayhem and cut power to a vast number of people.
As the storm pushed through, it flooded at least four hospitals, including in Pisa and Mugello.
Throughout Tuscany, train lines and highways were disrupted and schools were closed.
Hundreds of people were stranded, unable to get home, including about 150 stuck in Prato after a train line was suspended on Thursday night.
The mayor of Prato expressed shock at the force of the flood that devastated the city.
By early Friday, residents were working to clean the damage.
"A blow to the stomach, a pain that brings tears, but even after an evening and night of devastation, we are pulling up our sleeves to clean and bring our city back to normality,'' Matteo Biffoni posted on social media.
In southern Austria, wind and heavy rain on Thursday night led to landslides, blocked roads and power cuts.
The storm receded in northern France and the Atlantic coast on Friday, but heavy rain continued in some regions as emergency workers cleared away debris from the day before.
Corsica in the Mediterranean faced winds up to 140km/h and regions in the Pyrenees in the southwest were under flood warnings.
More than a half-million French households remained without electricity for a second day, mainly in the western region of Brittany.
Trains were halted in several areas and many roads remained closed.
French President Emmanuel Macron was travelling Friday to storm-ravaged areas of Brittany and Prime Minister Elisabeth Borne was travelling to Normandy.
Australian Associated Press