Severe flood warnings have been issued for the Devon and Cornwall coast amid storm warnings for most of the UK.
Rain and fierce winds are hitting parts of the UK, as what could be winter's worst storm moves in from the Atlantic.
In what could prove to be winter's worst storm, heavy rain and winds of almost 80mph (130km/h) have started to hit Wales and south-west England.
Emergency services said trees had been uprooted and power lines brought down in south-west England, where winds have reached almost 80mph (130km/h).
Emergency services said trees had been uprooted and power lines brought down in the South West. In Wales, 170 people were told to evacuate a caravan park.
Severe flood warnings have been issued for the Devon and Cornwall coast. In St Brides, Newport, 170 people were told to evacuate a caravan park overnight.
The Met Office also forecasts blizzards and heavy snow for central Scotland.
Meanwhile, forecasters say central Scotland will see blizzards and snow.
The Environment Agency is urging people to stay away from exposed coastal areas and to check for flood warnings in their area.
The Environment Agency is urging people to stay away from exposed coastal areas and to check for flood warnings in their area.
Cancellations
Garage roof
By 0400 GMT on Monday there were seven severe flood warnings in place in Devon and Cornwall and 44 other warnings in locations including southern England, and the Severn and Mersey estuaries.
By 0445 GMT on Monday there were seven severe flood warnings in place in Devon and Cornwall and 44 other warnings in locations including southern England, and the Severn and Mersey estuaries.
P&O Ferries said it had cancelled its Sunday sailing from Portsmouth to Bilbao, and from Bilbao to Portsmouth on 11 March.
The storm, which forecasters have been predicting for several days, has already left considerable damage and disruption in its wake, according to reports.
FLOODLINE Call 0845 988 11 88
FLOODLINE Call 0845 988 11 88
The company's website also said sailings between Dover and Calais were delayed by up to an hour because of the weather conditions.
In Devon, winds have torn off a garage roof in Torquay, and a power line near Slapton was reported to have been brought down.
A spokesman for Gatwick airport said if the weather was as bad as predicted, travellers could face delays or cancellations.
The Taymar Bridge has been closed to high-sided vehicles as winds in the Plymouth area reached speeds of 76mph.
Ministerial concern
In Cornwall, emergency planning teams provided stand-by supplies of sandbags and called in extra police to work overnight on Sunday and from early Monday.
Prime Minister Gordon Brown and senior government officials held talks on Sunday afternoon about the threat from the storm and checked local authorities were prepared for floods.
Overnight, the fire service received calls of cables arcing in Porthleven, causing a brief power cut.
Ministers are said to be most concerned about floods around dawn, when sea tides are at their highest.
Dorset police also received reports of fallen trees and a telegraph pole.
Evacuation rest centre
Forecasters said the storm may have reached its peak in the South West but further damaging gusts were expected along the coast on Monday evening.
On Sunday night, police in south Wales advised about 170 people to evacuate Lighthouse Park Caravan Site, in St Brides, over fears of flooding and structural damage.
Huge waves are expected to hit the UK coast.
Huge waves are expected to hit the UK coast.
Police in south Wales have advised people at a caravan Site in St Brides, Newport, to evacuate their homes because of possible flooding and structural damage.
In nearby Gold Cliff and Redwick, residents in coastal homes were also advised to evacuate.
In nearby Gold Cliff and Redwick, residents in coastal homes were also advised to evacuate.
Newport Leisure Centre has been set up as an evacuation rest centre by the city council.
A handful of locals spent the night at Newport Leisure Centre which the city council set up as an evacuation rest centre.
In west Wales, the worst hit areas were expected to be Amroth, Newgale, Dale, Solva and the centre of Haverfordwest in Pembrokeshire.
The storm has already caused some problems on the roads and for rail and air travel, with further delays and cancellations anticipated for Monday.
We understand that people are fascinated by the sea but at times like this we do urge them not to go and watch the high waves Paul LeinsterEnvironment Agency
We understand that people are fascinated by the sea but at times like this we do urge them not to go and watch the high waves Paul LeinsterEnvironment Agency
Damage is expected across the county from high winds and there may be further evacuations in some areas at risk of flooding.
British Airways cancelled several short-haul and domestic flights out of Heathrow Airport on Sunday night, and both Heathrow and Gatwick advised travellers to check with airlines before leaving home.
In Cornwall, emergency planning teams had been preparing for high winds and floods.
P&O Ferries cancelled a Sunday sailing from Portsmouth to Bilbao, and another from Bilbao to Portsmouth on 11 March.
Stand-by supplies of sandbags were provided and extra police called in to work overnight Sunday and from early Monday.
The RAC is advising drivers to be prepared for hazardous driving conditions over the next few days.
Cornwall's emergency planning officer Steve Winston said a combination of factors, including high spring tides and a very low pressure system, could lead to a "severe" event.
The Environment Agency urged people living in low-lying exposed coastal areas of Wales, south-west and southern England, including Hampshire, the Isle of Wight, Sussex and Kent to monitor the weather closely.
High waves
The Met Office advised travellers to leave extra time for journeys, as rail delays were likely, with the worst weather expected to strike on Monday afternoon.
The Met Office advised travellers to leave extra time for journeys, as rail delays were likely, with the worst weather expected to strike on Monday afternoon.
The RAC advised drivers to be prepared for hazardous driving conditions over the next few days.
Ministerial concern
The Environment Agency's director of operations, Paul Leinster, said: "There will be a potent cocktail of strong winds, wave action and high tides from Sunday night through until Wednesday."
Prime Minister Gordon Brown and senior government officials held talks on Sunday about the threat from the storm and checked local authorities were prepared for floods.
The Environment Agency urged people living in low-lying exposed coastal areas of Wales, south-west and southern England, including Hampshire, the Isle of Wight, Sussex and Kent to monitor the weather closely.
The agency's director of operations, Paul Leinster, said there would be "a potent cocktail of strong winds, wave action and high tides" until Wednesday.
He said gale force winds were expected to combine with spring high tides to raise water levels along the coast by up to 1.5m over normal levels.
He said gale force winds were expected to combine with spring high tides to raise water levels along the coast by up to 1.5m over normal levels.
Mr Leinster said: "We understand that people are fascinated by the sea but at times like this we do urge them not to go and watch the high waves - it is extremely dangerous and only takes a few seconds for someone to be knocked off their feet, into the water."
"We understand that people are fascinated by the sea but at times like this we do urge them not to go and watch the high waves," he said.
"It is extremely dangerous and only takes a few seconds for someone to be knocked off their feet, into the water."
Do you live in the regions which could be affected by the storms? How are you preparing? Send us your experiences using the form below.
Do you live in the regions which could be affected by the storms? How are you preparing? Send us your experiences using the form below.
