Two people have been killed as fierce winds battered the country.
A 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 powerful storm has also led to the evacuation of thousands of families living on the east coast.
More than 10,000 homes in Norfolk, Suffolk and Essex are being evacuated after officials warned that the lives of people in the region could be at risk from the worst coastal tidal surge for over 60 years.
The Environment Agency (EA) has issued a number of severe flood warnings - the highest category, which are only issued when flooding poses a danger to life - to the east coast and north Wales as high tides and strong winds threatened to swamp the coastline.
In Norfolk, 9,000 homes are being evacuated as local officials attempt to stem the damage from the coastal surge.
A further 1,000 properties are to be evacuated in affected areas in Suffolk and some residents in Jaywick, near Clacton-on-Sea in Essex, are also being urged to leave their homes.
Local officials are setting up emergency accommodation facilities and handing out sandbags to help people protect their homes, police said.
Police in Humberside have also declared an emergency situation as they prepared for coastal surges from this evening.
The EA has issued more than 250 flood alerts across England and Wales, including 42 severe flood warnings which are only issued when flooding poses a "significant threat to life".
The agency said communities along the North Sea coast from Northumberland to the Thames Estuary and Kent, in addition to those on the Irish Sea coast from Cumbria down to Cheshire, could see significant coastal flooding later today and into Friday.
A spokesman said 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. However, some coastal flood defences could be "overtopped" by the combined effect of high tides, high winds and a large tidal surge, he said.
Across the country tens of thousands of properties have been hit by power cuts as winds of up to 140mph battered powerlines.
The Met Office said there had been severe gales of between 60mph and 80mph across Scotland and northern parts of England, and some mountainous regions in Aberdeenshire and Inverness-shire reported speeds of around 140mph.
It has also issued national severe weather warnings for strong winds.
The adverse weather has also caused chaos to the rail network.
This morning services for Scotland and parts of the north of England were suspended. Trains were halted at their nearest stations and passengers told to disembark after Network Rail said debris on lines and damage to equipment meant it was not safe to operate any services.
National Rail said t rain services in Scotland are starting to run again as routes are cleared of debris. However, s ervices north of Carlisle and Newcastle are still suspended.
A number of flights have also been disrupted by the bad weather.
And c losures, fallen trees, minor accidents and incidents of flash flooding are affecting the road network in parts of the country.
Environment Secretary Owen Paterson chaired a meeting of the Government's emergency Cobra committee this morning to discuss the response to the storm.
"The purpose of the meeting was to make sure that all of the preparations - which we have well in advance - will work together to benefit the public," he told BBC News.
"I would urge everybody to pay close attention to announcements by the Environment Agency, the Department for Transport and local government.
"In some areas of Norfolk, where evacuations have commenced, I would urge everybody to work closely and to cooperate with the local authorities."
Mike Jones, chairman of the Local Government Association's environment board, said: "Local authorities up and down the country are preparing to divert staff from their normal duties and have placed additional employees on standby to work with fire crews and other emergency services to get people help if they need it.
"Staff have been preparing for this since being notified by the Met Office and have been taking measures such as testing local defences, putting barriers in place to prevent the waters travelling inland and setting up local rest centres for affected communities. Plans have also been put in place to ensure that older and more vulnerable people are not put at risk and can still access the council help they rely upon.
"Residents and businesses in affected areas should also make some preparations such us putting up any property-level defences, listening to local media reports and subscribing to the Environment Agency's flood alert service."
:: People are being urged to check the Environment Agency website or follow @EnvAgency and #floodaware on Twitter for the latest updates on flood warnings.