Parts of England will be threatened with serious flooding for several days due to swollen rivers, the Environment Agency has warned.
Rainfall is expected to continue hitting areas along the rivers Severn, Wye, Ouse and Trent.
The agency has issued two severe danger-to-life flood warnings for Ironbridge and Shrewsbury in Shropshire, both along the Severn.
More than 100 warnings, meaning flooding is expected, and about 200 alerts, meaning flooding is possible, are in force across England.
The flood warnings come after snow fell on Northern Ireland, Scotland and northern England.
The Met Office has forecast more widespread wintry showers including rain, hail, sleet and snow.
It will be cold, with winds further plunging temperatures to between -2C and 4C across the UK.
A yellow warning for ice covering Scotland, Northern Ireland and much of northern England remains in force, with up to 6cm (2in) of snow forecast.
The warning covers nearly all of Scotland, and County Antrim, County Armagh, County Down, County Fermanagh, County Londonderry and County Tyrone in Northern Ireland.
It also applies to Derbyshire, Darlington, Durham, Gateshead, Newcastle upon Tyne, Northumberland, Cumbria, Greater Manchester, Lancashire, as well as North Yorkshire, South Yorkshire and West Yorkshire in northern England.
The warnings come after a third weekend of extreme weather including torrential downpours that started with Storm Ciara and continued with Storm Dennis.
The torrents are contributing to record-high river levels.
England has endured more than 141% of its average February rainfall so far, the agency said.
It warned the country needs to brace itself for “more frequent periods of extreme weather like this” because of climate change – as winter storms bring more heavy rainfall in a warming world.
Its chief executive, Sir James Bevan, is due to give a speech at the World Water-Tech Innovation Summit in central London this morning when he will call for a twin track approach to flooding – “better protection and stronger resilience” – to defuse the “weather bomb”.
“It means building back better after a flood, not simply replacing what we had before,” he will say, “making our communities more resilient to flooding so that when it does happen it poses much less risk to people, does much less damage, and life can get back to normal much quicker”.
Labour’s Chris Bryant has made an impassioned plea for greater government help after the floods.
Mr Byrant told the House of Commons: “We need money from the government, we don’t want talk of mutual aid. We need money and we need it now.”
Meanwhile, Downing Street has defended Prime Minister Boris Johnson’s continued absence from flooded areas, with officials insisting it is important not to “distract” from the ongoing effort to deal with the problem.
The prime minister has been receiving “regular updates” about the situation, while Environment Secretary George Eustice is “rightly” leading the government’s response, Number 10 said.
Caroline Douglass, director of incident management at the Environment Agency, said: “Flooding has a long-lasting and devastating impact on people’s lives.
“River levels remain high and communities along the River Severn, in particular Shrewsbury, Bewdley and Ironbridge, should be ready for potential flooding.
“Groundwater levels across parts of Dorset, Wiltshire, Hampshire and Sussex are continuing to rise and will lead to more flooding impacts later in the week.”
She added: “We have seen our third weekend of exceptional river levels and stormy weather; with the effects of climate change, we need to prepare for more frequent periods of extreme weather like this.
“People need to be aware of their flood risk, sign up to flood warnings, make a flood plan and not to drive or walk through floodwater.”
The agency said 1,000 staff per day have worked to operate flood defences and pumps, clear debris and repair damaged defences since Storm Dennis swept across the UK.
Some 3.7 miles of temporary flood barriers have been erected and flood defences have protected more than 25,000 properties, it said.
Mr Eustice, making a statement to the Commons, urged people living in at-risk flood areas to remain vigilant following record-breaking flooding caused by storms Ciara and Dennis.
He told MPs that 1,400 homes in England had been flooded, but recent improvements to flood defence schemes had reduced the number of homes that could have been affected.
In Wales, more than 600 households and a similar number of businesses have been hit, representing almost 25% of all the properties affected across the UK.
Mr Eustice also said that 18 gauges across 15 rivers had recorded their highest water levels on record, including the Colne, Ribble, Calder, Aire, Trent, Severn, Wye, Lugg and Derwent.