Storm Isha has left thousands of people in the UK without power after bringing heavy rain and winds up to 99mph.
Scotland, Northern Ireland, north-west England and Wales have been hit, and those in remote areas have been warned they might have no power until Tuesday.
Two people have died, including an 84-year-old man in Scotland after the car he was in crashed into a fallen tree.
From Tuesday, Storm Jocelyn will bring strong winds and rain to Northern Ireland and parts of Britain.
The next named storm – the tenth since September – is expected to bring wind gusts of between 55 and 65mph (89 and 105km/h) across north-western Scotland.
Gust speeds are not forecast to top levels seen during the height of Isha, which saw 99mph (159km/h) recorded in Northumberland. Some of the winds have been the UK’s strongest in 10 to 20 years.
Police Scotland said an 84-year-old man died after the car he was travelling in hit a fallen tree at about 23:45 GMT in Grangemouth, Falkirk, on Sunday.
In Northern Ireland, a man died after a tree fell on his car in Limavady, County Londonderry.
Power outages affected about 53,000 homes at the height of the storm in Northern Ireland.
Around 30,000 properties were without power across England, Wales and Scotland on Monday morning, according to Energy Networks Association (ENA) – which represents energy providers.
Prime Minister Rishi Sunak said the government was working hard with authorities to restore power to homes, adding that electricity had returned to almost 300,000 properties.
Lawrence Slade, from ENA, said some properties might remain without power until Tuesday, particularly in remote areas.
He said it had been difficult to coordinate engineer teams because the storm had affected most of the UK, barring a small pocket in the east of England.
“We’ve got to get engineers out but we can only do that when it is safe, when the winds have dropped down sufficiently,” he told BBC Radio 4’s Today programme.
He told the BBC that helicopters and drones would be deployed to help direct engineers into the affected areas faster.
In the Republic of Ireland, about 235,000 homes and businesses were hit by outages.
Meanwhile, dozens of schools wer closed on Monday, mostly in Scotland and Northern Ireland.
The highest gust so far recorded by the Met Office was 99mph at Brizlee Wood in Northumberland.
Transport Scotland said a gust of 107mph was recorded on the Tay Bridge.
Transport services largely recovered on Monday though some roads remained closed and rail lines blocked.
ScotRail, Gatwick Express, Great Northern, Southern, Thameslink and East Midlands Railway services faced disruption on Monday morning.
Hundreds of flights were cancelled with planes heading to the UK forced to divert to France and Germany leaving passengers stranded in airports abroad.
A number of trees at the Dark Hedges in County Antrim, Northern Ireland – made famous by TV series Game of Thrones – have been damaged and felled by the storm.
Two Met Office amber warnings took effect at 18:00 GMT on Sunday, covering the entirety of Scotland, Wales, Northern Ireland and large parts of England.
A rare red warning covered an area stretching from Thurso and Wick in the north of Scotland, Fraserburgh and Peterhead to the east and Cromarty and Nairn in the west.
An amber warning for wind – the second highest – across parts of northern Scotland will take effect at 18:00 on Tuesday, while two other yellow warnings for the rest of Scotland, Northern Ireland, Wales and large parts of England have also been issued.
Two yellow warnings for rain covering north-west England and the west coast of Scotland will also start on Tuesday.
Storm Jocelyn has been named as the next named storm by the Irish weather agency, with the Met Office saying it will bring further strong winds and heavy rain to the UK on Tuesday and into Wednesday.
BBC Weather presenter Helen Willetts said: “What is striking about Isha is how unusually widespread its reach has been with impacts felt right across the UK,” she said.
“After a week with little rain but snow instead, the storm brought around 50 to 100mm of rain in the wettest areas and as a result flood warnings escalated again.
“Although it’s not as severely windy now, showers, some heavy and thundery, will be accompanied by squally winds and will persist for much of today.”
Storm Isha is the ninth named storm of the season that began in September 2023, with Storm Jocelyn becoming the tenth.
If two more are named between now and August, 2023-24 will mark a new record.
The Met Office names storms when they have the potential to cause disruption or damage. The agency says it is easier for people to follow the progress of a storm on TV, radio or social media if it has a name.
“In terms of naming storms, the UK has reached the letter ‘H’ earlier than in any previous season,” BBC Weather presenter Darren Bett said.
“This season could see the highest number of storms since the naming of storms started in 2015. Coincidentally, it was that year that brought a record 11 storms – up to the letter K,” he said.
Storm Jocelyn, however, likely to pass a little further to the north of Scotland and not be as intense, he added.
Heavy rain this week could also lead to flooding, the weather agency said. As of 11:00 on Monday, the Environment Agency in England had issued 19 flood warnings, where flooding is expected, and 83 flood alerts, where flooding is possible. There are 36 flood warnings in place in Scotland and one in Wales.
The impact of climate change on the frequency of storms is unclear but a warming atmosphere makes extreme rainfall more likely.
The world has warmed by about 1.1C since the industrial era began.
