Flood waters are reported to be receding after the worst tidal surge for more than 60 years hit coastal towns along the east coast of Britain.
Thousands of people were evacuated from their homes and spent the night in temporary accommodation as officials warned lives could be at risk.
The North Sea surge hit the north Norfolk coast early yesterday evening and headed south throughout the night.
The fierce Atlantic storm - which has already claimed two lives - caused widespread disruption yesterday, but some agencies this morning said that the expected flooding overnight was less severe than expected.
Northumbria Police tweeted: "Early indications are that the tidal surges in our area this morning are less than what we saw yesterday."
Essex Police said the flood situation was now been downgraded from a severe flood warning to a flood warning, and that the county had escaped the worst of the weather.
Military personnel from Colchester Garrison helped emergency services during the night in Maldon, and t he majority of people evacuated from their homes have now left rest centres, police said.
More than 10,000 homes on the coast were last night earmarked for evacuation after officials warned that the lives of people in the regions could be at risk.
In Boston, Lincolnshire, more than 250 people were taken to evacuation centres last night, and 200 were reported to be at a centre in Clacton-on-Sea in Essex.
Some North Sea oil platforms were also evacuated, the BBC said.
The Environment Agency has issued 45 severe flood warnings - the highest category, which are only issued when flooding poses a danger to life - covering coastal areas in East Anglia, the North Sea coast and south-eastern parts of England as high tides return again this morning.
Yesterday saw the brunt of the storm's impact.
One man died after he was struck by a falling tree in a park in Retford, Nottinghamshire, and a lorry driver was killed when his HGV toppled on to a number of cars in West Lothian, Scotland.
The Army was called in to assist firefighters and police in Norfolk.
Across the country more than 100,000 properties were hit by power cuts as winds of up to 140mph battered powerlines.
Northern Power Grid said 20,000 properties were affected in the North East, Yorkshire and North Linconshire.
Humberside Police said launched a search and rescue operation for three people who may have fallen into the River Humber close to Flixborough.
The force warned the public not ignore flood warnings, saying some people had been risking their lives by running into the tide.
In Norfolk, 9,000 homes were evacuated, mainly in the Great Yarmouth area, as officials attempted to stem the damage from the coastal surge. Soldiers in the town helped build flood barriers.
The Ministry of Defence said 60 Light Dragoons, based at the Swanton Morley Army base in Norfolk, were helping with the effort.
At Blakeney in north Norfolk, the water breached the quay at about 5.30pm.
Within 30 minutes the floods had advanced some 165ft (50m) up the village's main street. Water reached window height and at least one car was seen being swept away.
Allan Urquhart, who has lived on the seafront for eight years, took a rowing boat to the King's Arms pub to collect a friend.
He said: "I'm going to row back to the house and we'll stay upstairs tonight.
"We've put sandbags in place so hopefully we'll be OK. I'm as confident as I can be.
"This is the worst flooding I've seen so it could be a difficult night for lots of people."
Staff were seen baling water from the window of the King's Arms as the surge reached bar height.
Cliff Park High School, which was being used to house evacuees near Yarmouth, was full by mid-evening, Norfolk Police said.
A further 1,000 properties are expected to be evacuated in affected areas in Suffolk.
Officials are setting up emergency accommodation facilities and handing out sandbags to help people protect their homes.
A spokesman for Suffolk Police said the surge was expected to be an hour earlier and slightly higher than predicted.
Residents from more than 60 streets around Jaywick in Essex have been advised to leave their homes, Essex Police said.
In Kent, more than 500 properties were evacuated in areas including Sandwich, Seasalter and Faverhsham.
A spokesman for the EA said that in some areas sea levels could be higher than those during the devastating floods of 1953 - which battered the east coast of England and claimed the lives of hundreds of people.
Defences built since then - including the Thames and Hull Barriers - mean that many parts of the country are much better protected, he said.
The Met Office said the Atlantic storm brought severe gales of between 60mph and 80mph across Scotland and northern parts of England yesterday, and some mountainous regions in Aberdeenshire and Inverness-shire reported speeds of around 140mph.
The adverse weather has also caused chaos to the transport network, with rail services for Scotland and parts of the North of England suspended.
Environment Secretary Owen Paterson, who chaired two Cobra meetings, said: "It is really important that people take steps to prepare for flooding, which is likely to occur overnight.
"Clearly our priority is public safety and I urge people to act on the advice from the environment agency, police and local agencies."
:: People are being urged to check the Environment Agency website or follow @EnvAgency and #floodaware on Twitter for the latest updates on flood warnings.
Norfolk Police said Cromer Pier had been closed to the public because of storm damage.
Police in Yarmouth urged "sightseers" to stay away, saying they were placing themselves at "significant risk".
They said crowds, including people with small children on their shoulders, had been seen gathering close to the seafront.
Chief Inspector Kate Thacker said: "Some of these people have no concept of the danger they are putting themselves in and we are urging pedestrians to keep away from the flood water and seafront and for traffic to avoid the town centre."
Two rescue centres in the town were reported to be full.
Overnight, police went house to house in Ipswich to warn them of unusually high water.
A rescue centre was set up to house those displaced by flooding.