Britain was lashed by hurricane-force winds that reached nearly 100mph as Storm Imogen battered southern parts of the country and left commuters braced for havoc on the transport networks.
Gales and heavy rain have forced road closures and delays to rail services, with airports warning flights may be disrupted.
Almost 300 Environment Agency flood warnings are in place across the UK amid heavy downpours, with 59 warnings calling for “immediate action”, particularly in the south west and Wales where parts are expected to see up to more than 1.5ins (40mm) of rain during Monday.
Rail services in Wales, the south west and in southern areas are being disrupted due to strong winds, with speed restrictions and cancellations, the Severn Bridge was closed eastbound and restricted westbound because of strong winds and services from ferry companies Brittany and P&O are cancelled and delayed.
Gatwick airport also warned passengers flights could be delayed because of bad weather.
The Met Office has issued an amber “be prepared” wind warning for Wales, the south west, the south coast and London and south-east England, while coastal areas are expected to be lashed with large waves.
Forecaster Emma Sillitoe said the winds would be some of the worst so far this winter, not far off gusts of 105mph recorded last month in Shetland, Scotland.
She said: “We are looking to see gusts of 60-70mph quite widely, hitting the south west, Devon and Cornwall and moving across southern central parts towards London through the day. It is going to be picking up towards 70mph around lunchtime in London.
“We have seen 96mph at the Needles off the Isle of Wight and gusts to 80mph are likely, especially along northern coasts of Devon and Cornwall and along the Bristol Channel as well.”
Almost 5,000 homes in the South West, Midlands and Wales have been left without power due to high winds.
Engineers have been working through the night to restore affected services, Western Power Distribution said.
Highways England warned motorists in southern England to check forecasts and road conditions before travelling due to strong winds forecast up to 6pm.
The A35 running along the south coast between Devon and Hampshire has been closed by Dorset Police in both directions between the A354 and B3150 near Dorchester due to flooding, the agency added.
It said on its website that as a result of the strong winds, Highways England has issued a severe weather alert for “high-sided vehicles, caravans and motorbikes, which are advised to take extra care when travelling, due to the increased risk of vehicles being blown over”.
Traffic crossing between England and Wales is being diverted in both directions via the M4 following restrictions on the M48.
Rail passengers travelling in southern England and Wales face major delays for much of the day as high winds disrupt services.
Delays, alterations and cancellations are expected, while speed restrictions are in place on Arriva Trains Wales, Great Western Railway, the Gatwick Express, South West Trains, Southern and Thameslink services due to high winds which are likely to last until around 6pm.
National Rail Enquiries said coastal routes are likely to be most affected and warned travellers to check services before they travel.
Bad weather and stormy seas are also disrupting cross-channel ferry services, with the Port of Dover temporarily closed overnight due to wind and strong sea swells.
DFDS and P&O ferries between Dover and Calais are affected, while services from Liverpool to Dublin and from Newhaven to Dieppe are cancelled.
There are major delays and cancellations on Brittany Ferries crossings between south coast ports and northern France, while journeys between the UK and Spain in the coming days are also disrupted.
Gatwick Airport also warned flights may be disrupted. A spokesman said: “Due to air traffic restrictions due to adverse weather, some flights may be subject to delay. Passengers are advised to check the status of their flight with their airline.”
Meanwhile, a major river search is under way for a man missing in Taunton.
Avon and Somerset Police were alerted at 8.15am by a member of the public to reports that a man had entered the River Tone, near to Priory Bridge Road.
“We were called just about 8.15am by a member of the public to reports of a man in the River Tone,” a police spokesman said.
“We are in attendance with the ambulance and fire service and we are searching for the man. As yet we have not found anyone.”
The spokesman added that inquiries were under way to try and establish how the man entered the water.
As winds of around 80mph were recorded there were scores of reports of minor damage as Storm Imogen hit the UK, with people posting pictures on social media of felled trees, downed scaffolding, garden trampolines blown into properties and damaged homes.
The Forestry Commission also said it had closed a number of forests due to dangers from strong winds. Coastlines in the South, West and Ireland have been battered, with seafronts lashed by huge swells.
Waves of up to 14 metres are expected off the coasts of Devon and Cornwall, though tides and currents mean they are unlikely to hit land.
Storm Imogen is expected to track eastwards across the UK throughout Monday, bringing gusts of up to 70mph in the South and 60mph in the middle of the country.
Scotland will escape the worst of the weather, with winds only reaching 40mph.
Ms Sillitoe said: “It is going to be a very windy day for most of today, and gusts are going to be quite strong. We are also going to see some prolonged showers throughout the day, more prolonged in the West where there will be the risk of hail and thunder.
it is also going to be feeling very cold today, with temperatures getting up to 9C (48.2F)or 10C (50F) in the London area but feeling closer to 2C (35.6F) with the wind chill factor. Winds are expected to gradually ease through the afternoon and evening.
Later, Avon and Somerset Police said their units have been stood down from the search for the man in the River Tone. “We’re satisfied there’s no one in the water and the information we originally received was incorrect,” a force spokesman added.