The Met Office said there would be a "multi-pronged attack" of wind, rain and snow striking the country tomorrow. The heavy rain could lead to more flooding as downpours of up to 40mm (1.6 inches) could fall in just six hours, a spokesman said.
As well as surface water problems the rain could also impact on already full to bursting rivers while some coastal areas could be at risk as blustery conditions could bring large waves.
Met Office forecaster Steven Keates said coastal regions could see gusts of 70mph.
In the highlands of Wales, northern England, Northern Ireland and Scotland, the rain could turn to snow, with 5cm to 10cm (2-4 inches) falling above 300 metres and perhaps as much as 20cm (8 inches) above 400 metres.
The weather has already caused problems for commuters after Network Rail was forced to close part of the West Coast Maine Line yesterday due to high winds.
Windsor, Maidenhead and communities along the Thames in Surrey remain at high risk of flooding from the River Thames today and Friday, with significant flooding of homes and businesses expected.
The Thames has recorded some of its highest levels for 60 years, the Environment Agency said, and while water levels may fall today they are expected to rise again on the Thames and Severn, affecting places already experiencing flooding.
Flooding continues on the Somerset Levels and Moors, and there is still a high risk of coastal floods in Dorset.
Environment Agency chief executive Paul Leinster said: "We are continuing to see the very real and devastating impacts that flooding can have on communities and businesses. We know the distress that flooding can cause and are doing everything we can to reduce the impacts.
"Some communities will see a brief respite today, but unfortunately the risk of flooding will continue. We ask people to remain vigilant and take action where necessary.
"We expect to see river levels rising again with more rain forecast for Friday and Saturday."
In Winchester, Hampshire, Environment Agency teams have been creating a temporary flood storage area to cope with water levels on the River Itchen.
The agency has also been out across the country, ensuring blockages are removed from rivers, putting up temporary defences and supporting the deployment of sandbags by local authorities.
Christchurch Borough Council in Dorset has come under fire from ministers after it emerged they were charging locals £30 for four sandbags on the basis that the situation in the area was not an emergency.
Deputy Prime Minister Nick Clegg rejected calls for cash to be diverted from the UK's £11 billion foreign aid budget to help flood victims.
The Government will review flood defences after waters have receded, said Mr Clegg, promising: "I will make sure, as Deputy Prime Minister, that as we review things we do so in a way that makes lasting change, where we can make that change, where we can afford it and deliver it."
He said he backed dredging in rivers where it could make a difference, but warned that it should not be viewed as a "magic wand" solution.
The latest bad weather will compound the misery for communities who have seen rivers rise to record levels and prolonged flooding in what has been described by army chief Major General Patrick Sanders as an "almost unparalleled" natural crisis.
Bank of England governor Mark Carney said the chaos even threatened to derail Britain's economic recovery.
Since early December, 5,800 properties have been flooded across the country, with high winds causing further problems yesterday.
Wiltshire Police said a man in his 70s died in a suspected electrocution while attempting to move a tree which had brought down power cables near Chippenham.
A lorry driver was taken to hospital after high winds blew over his vehicle in Bristol, while another man received treatment after becoming trapped under a fallen tree in Chivenor, Barnstaple, Devon.
Road and rail travellers endured another miserable day, with wind and rain closing major routes and wrecking train services across the UK.
Energy and Climate Change Secretary Ed Davey said the current conditions showed the "possible consequences of a world in which extreme weather events are much more likely".
At an event hosted by think-tank the Institute for Public Policy Research, Mr Davey delivered a stinging attack on the fringes of the Conservative Party and Ukip for "parroting the arguments of the most discredited climate change deniers".
But in questions after the speech, he insisted that he worked very closely with Environment Secretary Owen Paterson, who has come under fire from green groups for his climate scepticism, on flooding, and that he had support from around the Cabinet table including from the Prime Minister.
The first priority was to tackle the consequences of the current flooding, power cuts and transport disruption, Mr Davey said.
But when it came to assessing the long-term causes of flooding, Mr Davey said he liked to listen to the scientists and pointed to the assertion by the Met Office in the past week that there was a link between climate change and the winter storms.
"Climate change scientists have been warning for some time there will be an increase in extreme weather events. I think we do need to take what the scientists are telling us extremely seriously."
He said there was a need to continue with investment to adapt society and the economy to the climate change that was already happening as well as being ambitious with efforts to stop global warming getting worse.
Communities Secretary Eric Pickles announced in a written statement to MPs that councils would be able to reclaim emergency spending on flood relief until the end of May in recognition of "the extended nature of the weather".
"This vital extension will give councils the reassurance that they will have time to deal with the effects of the weather and still have time to properly assess local costs," he said.
Some 80% of payments under the Bellwin scheme, which provides emergency financial assistance to local authorities during exceptional circumstances, will also be made now, rather than forcing councils to wait until the situation has cleared up.
"This means that local authorities will have access to the cash they need right now to deal with the pressing problems caused by the weather.
"Local authorities simply need to put in a request to my department and we will pay up to 80% of spending which is eligible under the Bellwin scheme," said Mr Pickles.
He added: "For the avoidance of doubt, where local authorities issue sandbags as a result of an emergency the cost can be claimed through the Bellwin scheme. In that context, I wish to be clear that no local authority should be charging their residents for sandbags."
Prime Minister David Cameron has chaired the first meeting of a new Cabinet committee set up to coordinate long-term plans on flood recovery and resilience.
The committee agreed to review the Bellwin scheme, look at the resilience of the transport network to extreme weather, and review the investment guidelines on flood defences, which have come under fire for being too strict to provide needed protection.
Mr Cameron said that, while the country was in the grip of the severe weather, it remained the Government's immediate priority to do all it could to help affected local communities and coordinate the emergency response.
"We are doing everything we can to help people and businesses deal with the flooding and get back on their feet. And through this new Cabinet committee we are doing all we can to ensure resilience in the future," he said.
Hundreds of properties remain at risk of flooding, the Environment Agency has warned, as southern England prepared for another battering by the winter storms
With the Met Office warning of more heavy rain and high winds with gusts of up to 80mph, the EA said it could be weeks for inundated communities to get back to normal.
"I expect we will see hundreds of properties looking to flood," EA programme director Toby Willison told a Whitehall press briefing.
The Government's chief fire and rescue adviser Peter Holland said that 70% of the fire and rescue services in England and Wales were now involved in the flood relief effort.
"We are now seeing the largest deployment of fire and rescue service assets since the Second World War," he said.
Tony Glover of the Energy Networks Association said that 56,000 homes were still without power after yesterday's storm and that it was unclear when they would have their electricity restored.
"We are hoping practically everybody will be restored," he said.
"We are working very hard to get people back on in very, very difficult circumstances."