Storm Ali was declared a "major incident" today after wreaking havoc across the British Isles with wind speeds of more than 100mph and killing two people.
The storm claimed its first life this morning when a woman died after her caravan was blown from a cliff in high winds in County Galway, western Ireland.
She has been named locally as Elvira Ferrai from Switzerland.
In the afternoon, a young man was killed and another was injured by a falling tree as they worked at a country park in Northern Ireland.
It is understood the men were doing contract work for Northern Ireland Water when the incident happened in Slieve Gullion Park, near Newry, Co Down, on Wednesday afternoon.
The man who died was aged in his 20s. The injured man, who is aged in his 40s, had been taken to hospital.
A spokeswoman for the Police Service of Northern Ireland (PSNI) said: "Police attended the sudden death of a man, aged in his 20s, in the Slieve Gullion Park, Drumintee Road area of Newry this afternoon."
Police said there were no suspicious circumstances and the incident was being investigated by the region's Health and Safety Executive.
Amber and yellow wind warnings are in place for Northern England, Scotland and Northern Ireland until 10pm on Wednesday. There is a yellow warning for rain for Northern England and Wales in place from 4am to 10pm on Thursday.
In Scotland, police said a "major incident" has been declared in Dumfries and Galloway due to the storm, with roads and ferries all being affected by the severe weather.
The extreme weather cost a woman her life at around 7.45am after a caravan was blown off a cliff at Claddaghduff, Co Galway, Ireland, while she was inside it. The caravan was smashed to pieces on the rocks and sand.
A statement by Garda confirmed a search was carried out at the scene on the beach and “a short time after the body of a female in her 50s was recovered”.
Speaking on the incident, Irish President Michael D Higgins expressed his condolences to the woman’s family and said: “Today’s strong winds can result in dangerous situations.”
“I would urge everyone to heed the warnings by the authorities and take caution when travelling or when out in the open,” he added.
Meanwhile, a woman was seriously injured after a tree fell on to her car in Tarporley, Cheshire.
A spokesman for Cheshire Fire and Rescue Service said crews were called to Forest Road just after 1.30pm when the tree fell on the car, trapping the woman inside.
Firefighters worked with a tree surgeon to help remove the tree before cutting the roof of the vehicle off and freeing the woman.
She was taken to hospital by air ambulance.
The Met Office said gusts of 91mph hit Killowen in County Down, 77mph winds were recorded in Kirkcudbrightshire in Scotland, 74mph gusts hit Capel Curig in Wales and 68mph was recorded in St Bees Head, Cumbria.
Irish forecaster Met Eireann said the strongest gusts in the hour leading up to 10am reached speeds of 120km/h (74.5mph) at Mace Head in County Galway, 98km/h (60.9mph) at Dublin Airport and 107km/h (66.5mph) at Shannon.
Gale-force winds from Storm Ali have caused damage to the electricity network affecting more than 140,000 homes, farms and businesses.
Terrifying footage taken at Dublin Airport also shows Storm Ali wreaking havoc as a plane was forced to abandon its landing as eyewitnesses saw it “rocking from side to side”.
The Ryanair plane can be seen suddenly veering up and back into the sky.
In Scotland where a major incident was declared, the Forth Road Bridge, Clackmannanshire Bridge and Queensferry Crossing have put restrictions in place while the Tay Road Bridge is shut to all traffic having recorded winds of nearly 92mph.
Elsewhere, tug boats were called to the Nautica cruise ship which slipped its berth in Greenock.
Strong winds saw the vessel - which had 478 passengers and 26 crew - leave the dock after its mooring lines parted. There have been no reports of injuries.
A section of Princes Street in Edinburgh has been closed after parts of a shop roof flew off in strong winds.
Police Scotland was alerted to lead falling from the Topshop building at around 12.30pm on Wednesday.
ScotRail said it was dealing with "severe disruption" across all of Scotland and advised people not to travel.
Dublin Airport said it has had 42 cancellations and eight diversions.
Photos posted on social media showed trees down in Galway while Dublin Fire Brigade posted about falling trees damaging cars, with one photo showing a smashed windscreen.
Six areas of Carlisle in north-west England have also suffered a power cut with Electricity North West engineers working to restore supply.
Superintendent Mark Pannone of Cumbria Police said: "We are getting a high number of calls about disruption, with trees down on some roads.
"We would urge people to be aware of their surroundings and take care.
"We would ask drivers to leave themselves plenty of time for travelling and to monitor local radio and websites for any travel information.
"Our advice to drivers is to slow down and to drive to the conditions you face."
The worst of Ali's weather was expected in the north, although areas outside the official weather warnings were unlikely to escape wet and windy conditions.
While southern parts of England and Wales could reach continued unseasonable highs of up to 24C (75F), it was expected to feel cooler due to the strong winds, Met Office meteorologist Mark Wilson said.
The unsettled weather is due to last right through the week but an improvement is expected early next week as drier weather is set to take hold.
Ali is first on the storm names list for 2018-19 announced by the Met Office and Met Eireann, which has run the Name Our Storms scheme for four years.
The season's names have been compiled from a list of submissions by the public, choosing some of the most popular names and also selecting those which reflect the nations, culture and diversity of the UK and Ireland.