The Environment Agency has warned there is a potential threat to life due to flooding of three rivers in Cornwall.
At Polperro, south Cornwall, the level of the River Pol has been recorded at 0.26m. The typical level is between 0.00 metres and 0.25 metres.
"River levels are rising and expected to flood out into the lower areas of the town causing significant hazard. This flooding is imminent, take the appropriate action now," the Environment Agency said.
Severe warnings are also in place at Bolingey Stream from Bolingey to Perranporth, and at the River Cober, in Helston.
Cornwall County Council has set up rest centres for flooding victims in Millbrook, Helston and Mevagissey for anyone who has been affected.
Fire and Rescue Service say they are already dealing with a number of major incidents in the county.
The rest of Britain is also bracing itself for more flooding and travel disruption, with forecasters predicting further heavy downpours.
A deep area of low pressure has moved in, bringing more heavy rain to areas already badly hit by Thursday's downpours.
Dave Throup of the Environment Agency told Sky News there are an "awful lot" of properties at risk, especially in the south west and Midlands.
He said: "The catchments are now completely saturated and we have spent the last day or so trying to make sure that the rivers are as clear as they can be.
"We've already protected 20,000 properties but we need to be vigilant."
He said nearly 400 properties have been flooded since Tuesday, while 9,000 homes and businesses have been told they are at risk of flooding.
The Environment Agency has issued 56 flood warnings and more than 187 less serious flood alerts.
Emergency teams have been working through the night and this morning to shore up defences, deploy temporary barriers, monitor river levels, clear blockages from watercourses and pump-out flood water from towns.
Sky weather producer Joanna Robinson said: "England and Wales could see 15 to 25mm quite widely, with up to 50mm possible in some spots.
"Between 6am and 6pm today 47mm of rain has fallen at St Mary's (Isles of Scilly), 28mm at Culdrose and Plymouth and 17mm at Exeter and Bournemouth.
"We can expect up to 60mm locally across parts of south Wales and the West Country by tomorrow morning with 30 to 40mm quite widely.
"Elsewhere across England and Wales there will be up to 25mm of rain, with lower amounts across Scotland, but local flooding remains a risk there after such a wet week.
"Gusts up to 70mph are expected for coastal areas of south-east England overnight, with inland gusts of 60mph. There is also the potential for some damage, particularly as the ground is saturated.
"It will be very windy across other southern areas, but the south-east likely to see the strongest winds".
South and west Wales and the West Country will be worst affected. Strong winds and possible severe gales are expected on Saturday night and Sunday morning,
"There's still some uncertainty about where the strongest winds will be, but it looks like southern counties of England will bear the brunt, with exposed parts seeing gusts up to 70mph," she said.
The AA's head of special operations, Darron Burness, said: "With more heavy rain forecast across the Midlands, Wales and the South West, road conditions in the affected areas are likely to only get worse as the ground is so saturated.
"Even if you think you know your local roads, don't be complacent, as flash-flooding continues to be a real risk and is catching people out."
Meanwhile, Network Rail said trains were likely to be suspended between Exeter and Bristol until Monday.
The majority of the UK was battered by storms on Thursday leaving hundreds of drivers stranded and thousands of homes without power. More than 100 people had to be evacuated as winds reached more than 86mph.
An elderly man died after becoming trapped in his 4x4 in floods in Chew Stoke in Somerset.
Three other people had a lucky escape after their car was swept down a swollen river in Warwickshire. The vehicle was carried more than 500 metres before a farmer managed to pull it to the water's edge.
A West Midlands Ambulance Service spokesman said: "Two elderly females and one male were treated for shock and hypothermia by ambulance crews."
In Torquay, Devon, several homes were evacuated after a landslide. Part of a cliff face was hit by a landslip after netting was washed away.