Britain is in the grip of an "unparalleled natural crisis", said the army officer in charge of the flood recovery effort.
As hurricane-force winds gusting at more than 160km/h lashed the country, forecasters warned the weather will get worse this weekend as a month's worth of rain falls in just 48 hours.
The chaos now threatens to derail Britain's economic recovery, Mark Carney, the Governor of the Bank of England warned.
The storms could knock as much as 13.8 billion ($27.6 billion) off the value of the UK economy, one expert warned. Richard Holt, of Capital Economics, said the area at risk represented around 13 per cent of the country's gross domestic product. A month's loss of output in those areas would reduce GDP by just over 1 per cent, he added.
The comments came as storms that have battered the southwest and Wales for weeks spread to the north of England for the first time this winter.
Parts of the transport network ground to a halt with trains forced to shelter in stations and motorways shut.
For the first time in two years, the Met Office issued a "red" weather alert for high winds, with gusts reaching 173km/h, while Premier League games were cancelled because of high winds for the first time in more than 20 years.
Major General Patrick Sanders, Assistant Chief of Defence Staff and the man in charge of the soldiers helping the flood response, said swathes of the country had turned into a "battlefield" against the rising water.
Describing the floods as "an almost unparalleled natural crisis", he said 2000 soldiers were already helping and another 3000 were on standby. Five regional brigades were bringing "crucial" organisational skills in Somerset, the Severn Valley and the Thames Valley.
The number of flooded homes rose to 5800, and more than 130,000 homes and businesses in England and Wales were without power as the storms brought down electricity cables.
Wales and the northwest were hit by winds gusting up to 173km/h in coastal areas, but today and tomorrow could see the worst weather yet this winter, as Atlantic storms dump another 100mm of rain on high ground in the southwest in just two days.
The downpour will be as bad as anything seen in January, and a Met Office spokesman said: "Because the ground is even more saturated than it was last month, the effect will be to make flooding even worse."
The Environment Agency said a number of rivers in the southeast and southwest, including areas of the Thames, were at their highest recorded levels and are expected to deluge communities that have so far been spared.
The Environment Agency had 16 "danger to life" severe flood warnings in place, 14 of them on the Thames and two on the Severn. A further 141 "amber" flood warnings and 281 "yellow" alerts covered much of England and Wales.
As the bad weather spread northwards, coastal flooding was expected on the northwest coast and the Dorset coast, while the threat of groundwater flooding continued in Hampshire, Kent and parts of London, the Environment Agency said.
Parts of Wales, the northwest, Derbyshire and the Chilterns could also have snow in the next 72 hours.
With experts warning that some flooded areas of southern Britain could remain underwater until May, and more storms still expected to hit the country, the Environment Agency moved to reassure citizens that flooding is unlikely to spread to further parts of the country.
For those who have already seen their homes and their livelihoods suffer, the bad news is that the floods affecting them are expected to persist and many will be left wondering how much worse it can get.
Jeremy Benn, founder of the JBA engineering consultancy, said flooding could cost 30,000 per house. "The current flooding is probably going to cost hundreds of millions in terms of direct damage, plus the cost of clearing up and disruption to business."