A lorry driver has died as fierce winds brought havoc to British roads.
Police said the driver died when his HGV toppled on to a number of cars in West Lothian.
There have been warnings of severe flooding in coastal areas and the possibility of householders being evacuated.
The Environment Secretary will chair a meeting of the Government's emergency Cobra committee to discuss the response to the storm, David Cameron said.
In a message on Twitter the Prime Minister said: "I've asked Environment Secretary Owen Paterson to chair a Cobra this morning on the storm disruption - ensuring everything is being done."
The entire rail network in Scotland was suspended, with trains halted at their nearest stations and passengers told to disembark after Network Rail (NR) said debris on lines and damage to equipment meant it was not safe to operate any services.
NR spokesman Nick King said: "We cannot continue to run trains with the levels of wind we are seeing."
Train companies in England were operating amended timetables, with the changes likely to last until the afternoon and t he bad weather also hit a number of flights.
Around 20,000 homes were left without power as rain and winds gusting up to 140mph battered Scotland.
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.
Further south, severe flood warnings - the highest category, warning of danger to life - were issued for large areas of East Anglia as high tides and strong winds threatened to swamp the coastline.
The Environment Agency (EA) issued 25 severe flood alerts for the region with another in Sandwich, Kent, as gale-force winds threaten to whip up the most serious tidal surge for 30 years.
In some places, sea levels could be as high as those during the the devastating floods of 1953, the EA said, although flood defences since then, including the Thames, Deptford and Hull barriers, should provide better protection than 60 years ago.
So far the EA has issued more than 200 flood alerts across England and Wales, with 3,000 properties expected to suffer from flooding in the next 24 hours.
EA spokesman Peter Fox said: "The most important thing is that along the east coast (of England) the high tide will be hitting in the hours of darkness this evening and tonight, so people really need to take the daylight hours today to prepare for the coastal and tidal flooding that we are predicting."
Mr Fox said evacuation in "key areas" was being discussed with police.
Areas most at risk include the North Sea coast from Northumberland down to the Thames Estuary and Kent.
The tidal reaches of the River Trent, Nottinghamshire, could also be affected.
On the west coast, severe gales and large waves combined with high water levels are expected from Cumbria down to Cheshire.
The Thames Barrier was closed last night to protect London, and other defences have been activated at Colne in Essex and in Hull.
Natural Resources Wales is urging people along the North Wales coast between eastern Anglesey and Liverpool to be prepared for flooding, and the Scottish Environment Protection Agency has issued flood warnings to 24 regions.