Hundreds of homes have been evacuated and thousands left without power in England, Scotland and Northern Ireland as Storm Frank brings more heavy rain.
There are three severe flood warnings, indicating danger to life, in Croston, Lancashire, where villagers are braced for the second flood in a week.
About 300 homes are being evacuated in Hawick in the Scottish borders, with more likely in nearby Peebles.
Fire crews are also using boats to rescue people from a cut-off village.
There are 46 flood warnings, requiring immediate action, in England and Walesand more than 60 others in Scotland.
In Dumfries and Galloway, in Scotland, the village of Carsphairn has been cut off and fire crews have been rescuing people from 30 properties by boat. The River Nith has also spilled over its banks causing flooding in the town of Dumfries and a severe flood warning has been issued for the Whitesands area.
In Northern Ireland, thousands of homes have experienced power cuts, air passengers have been delayed and fallen trees have caused problems on the roads.
eets in Dumfries were seriously affected from early afternoon
Meanwhile, in North Yorkshire, soldiers have evacuated homes near a bridge in Tadcaster after it collapsed, prompting fears of flooding and a possible gas explosion.
The town’s 18th-century stone bridge over River Wharf collapsed on Tuesday, causing a nearby gas pipe to rupture.
People watched the storm-battered masonry crumble into the swollen river, before running away as a wave headed towards the bank and a strong smell of gas leaked from exposed pipes. A severe weather warning for the town has now been lifted.
A man has been arrested on suspicion of theft outside a flood-damaged home in West Yorkshire
Homes in Ballater, Aberdeenshire, have been evacuated as the River Dee floods, with fire crews requesting boats to help them reach some properties
About 1,700 homes in the north east of Scotland and 1,600 in Argyll have lost power, with further power cuts across the Highlands, Outer Hebrides and Northern Isles
About 20,000 homes and businesses in Northern Ireland lost power overnight. Some 500 are still without it and electricity companies say more homes may be affected
December, so far, has been a record-breaking month for rainfall, Met Office figures show. The heaviest fell in Capel Curig in Wales, which had 1,000mm (39 inches) of rain, well above its December of 300mm (12 inches)
Passengers on nine flights into Belfast International Airport were temporarily held on planes due to high winds. Two other inbound flights had to be diverted to Dublin
In Wales, more than 1,400 properties in Carmarthenshire, Pembrokeshire, Swansea and a handful in Ceredigion lost power but most have since been reconnected
Part of the Victorian Birnbeck Pier in Weston-super-Mare has collapsed into the Bristol Channel amid high winds
A red weather warning has been issued for the Isle of Man, with up to 100mm (nearly four inches) of rain expected on high ground
BBC Weather’s Matt Taylor said between 80mm and 120mm (three to five inches) of rain was expected over Cumbria and central and southern Scotland, with rivers in Dumfries and Galloway likely to rise.
Scottish coasts were experiencing wind gusts of up to 70mph (112km/h), he said.
Live flood warnings from the Environment Agency and the Scottish Environment Protection Agency.
Note: the Environment Agency and the Scottish Environment Protection Agency display their flood alert data differently. While the Environment Agency highlights individual rivers only, in Scotland the entire region is coloured to indicate the level of alert. This map and flood alert data are supplied to the BBC by third parties. The BBC is not responsible for its accuracy and you use it at your own risk.
Media captionStorm Frank inundated Tramore in Ireland with sea foam
In the Republic of Ireland, gales and torrential rain have closed roads, hit rail services and cut power to 4,200 homes and businesses.
In Wales the stormy weather has caused three separate crashes on the M4 where there was standing water on both sides of the motorway between junctions 35 at Pencoed and 36 at Sarn.
National Rail has said it is reopening some lines in Scotland following flooding on the Scottish railway network.
In Croston, which was hit by floods on Boxing Day, an RAF Chinook helicopter delivered 400 tonnes of sandbags on Tuesday in a bid to shore up the nearby River Douglas in preparation for Wednesday’s storm.
Mark Cowley, vice chairman of the parish council, said: “Everybody’s worried. They’re still shell-shocked from what happened on Boxing Day.”
Meanwhile, police in York said it was “extremely disappointing” that thieves had broken into homes submerged in flood water. They said dry goods had reportedly been stolen from outside homes, tools taken from sheds and a back door forced open.
North Yorkshire Police’s acting Supt Mark Grange said: “It is impossible to comprehend why anyone would want to bring further suffering to those who are already in a very vulnerable situation.”
Environment Agency head Sir Philip Dilley returned to the UK earlier after cutting short his family holiday in Barbados.
He will travel to the north of England later to visit some of the flood-hit communities.
He said he had been “in very close contact” with senior agency staff throughout his Christmas break.
“Everybody can’t be everywhere at the same time,” he said, when asked about his whereabouts during the floods.
“I think we’ve been very effective and efficient in what we’ve been doing. There’s obviously some lessons to learn.”
On Tuesday, Communities Secretary Greg Clark announced £50m extra funding to help households and businesses affected by flooding in northern England. The government says it has now pledged more than £100m.