Coastal regions in southern Britain were lashed by strong winds, lightning and driving rain today, with top wind speeds reaching 100mph.
The lighthouse at The Needles on the westernmost point of the Isle of Wight reported gusts of between 95mph and 100mph.
But meteorologists said average wind speeds were closer to 70mph in exposed areas as storms swept the country.
In West Sussex, fire crews were called to two lightning strikes, and motorists had to be rescued from cars in Dorset after getting caught in flash floods.
The Environment Agency has 24 flood warnings in force, with the majority in southern coastal regions.
The worst of the weather will have passed over most of the country by early evening, and the storm is expected to move out to the North Sea and lose power overnight.
Forecasters said Sunday should see calmer weather.
But northern areas that escaped much of the ravages of today's storm will get a lashing on Monday, with winds of up to 60mph, and some areas in western Scotland will see gusts reaching 70mph.
Stephen Davenport, of MeteoGroup UK, said: "This is the strongest storm we have had this year, but it is just an autumnal storm, and not untypical for this time of year."
The storm developed off the west coast and was fed by the still-warm autumn sea temperatures, he said.
The stormy conditions have been causing disruption throughout the South and West.
In Haywards Heath, West Sussex, workers stranded by floodwater in four units on the Burrell Road industrial estate were rescued by boats.
West Sussex firefighters were also called out after a tree was brought down on power lines and caught alight.
In Wales, Pembrokeshire was the hardest hit, with widespread flooding of the county's road network trapping people in their cars.
Firefighters using a boat and a Land Rover rescued a woman stranded by floodwater in the Rosemarket, at Milford Haven.
In Haverfordwest, 12 people were rescued from a coach trapped in floodwater between Caneston Bridge and Cross Hands Road.
Floods in Tenby affected roads around the resort, blocking cars and trapping people inside them. A total of 14 people were rescued from vehicles in and around the town, with five of those trapped at Gumfreston.
Some cross-Channel sailings were disrupted due to the rough seas and winds gusting up to force 10, the Port of Dover said.
SeaFrance crossings from Dover to Calais and LD Lines services to Boulogne were subject to some delays.
A Port of Dover spokesman warned passengers to expect disruptions.
Many parts of Cornwall, including Padstow harbour, were also hit, the fire service said.
Brittany Ferries cancelled sailings from Plymouth to Roscoff and Poole to Cherbourg because of the severe weather.
In Dorset, five people, including a pregnant woman and two young children, fled their car when it was enveloped by floodwater at Whitchurch Canonicorum, near Bridport.
A Dorset Fire and Rescue Service spokeswoman said the water was up to the car bonnet by the time crews arrived, but all five had got out and were safe. The pregnant woman was checked over by ambulance staff.
Two people in a car were also pulled out of floodwater at Broadwindsor in Dorset and were unhurt.
In Bournemouth, the roof of a covered car parking area next to student accommodation was blown off in high winds, but no-one was injured.
Meanwhile, three oil rig workers were rescued by a lifeboat crew after their supply boat ran aground at Britain's most easterly point.
Lifeboatmen said the boat was washed on to a jetty at Ness Point, near Lowestoft, Suffolk, late last night as 45mph winds battered parts of the east coast.
A spokesman for the Lowestoft lifeboat crew said the men were unhurt but their boat was destroyed.
"There's a very old jetty on Ness Point and their boat had literally been washed on to it," he said.
"We got them off and left the boat there, but during the night another wave hit it and it is a write-off."
He added: "We were up to gale force out here. There were gusts of 45mph. It was rough. They'd been heading into Lowestoft to pick something up when they got into trouble."