Fierce winds have brought widespread disruption with thousands of rail travellers stranded and warnings of severe flooding in coastal areas and the possibility of householders being evacuated.
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 s pokesman Nick King said: "We cannot continue to run trains with the levels of wind we are seeing."
Around 20,000 homes were left without power as rain and winds gusting up to 114mph battered the north of Scotland.
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 18 severe flood alerts for the region with another in Sandwich, Kent, where high tides will be between 12.45am and 1pm tomorrow.
By 7am the EA had issued 140 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 the police.
The 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.
Areas most at risk of flooding 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.
Paul Leinster, chief executive of the EA, said: "Gale-force winds and large waves along the east coast of England are forecast during Thursday and Friday, coinciding with high tides and a significant coastal surge.
"Flooding of some coastal communities is expected and some defences could be overtopped by the combined effect of high tides, high winds and a tidal surge.
"Coastal paths and promenades will be highly dangerous as there is an increased risk of people being swept out to sea.
"The Environment Agency is monitoring the situation closely, working alongside partners including the emergency services, Met Office and local authorities. Environment Agency teams are out on the ground checking that flood defences and barriers are in good working order, monitoring sea levels and issuing flood warnings."
Only South Wales, the South West and southern parts of England escaped the high winds.
The Environment Agency warned that high water is due between 10.30pm and 10.45pm, when tide levels will be more than 10ft. Surges of almost six feet are expected.
Train companies in England were operating amended timetables, with the changes likely to last until the afternoon.
The bad weather also hit flights.
At Glasgow airport a number of domestic services were cancelled, including some involving British Airways. BA also had some flights axed at Edinburgh airport where there were also cancellations.
At Aberdeen airport, flights to Wick, Leeds Bradford and London City were among those that had to be cancelled, while at Leeds Bradford passengers were warned to expect delays.
Among Leeds Bradford flights that had to be axed were a Flybe service to Southampton, a BA flight to Heathrow and a KLM flight to Amsterdam.