Strong winds of up to 90mph brought by Storm Dudley could pose a danger to life on Wednesday, forecasters have warned.
And when it clashes with incoming Storm Eunice, people should brace themselves, they say. The hashtag #TwoStorms is being used by the Met Office.
It has issued an amber warning for “very strong and disruptive” winds which could cause widespread chaos, including a “good chance” of power cuts and disruption to transport services.
The warning says: “Injuries and danger to life is likely from large waves and beach material being thrown onto coastal roads, sea fronts and properties.”
In place from 4pm until midnight, the alert covers a large belt across the middle of the UK, including regions north of Hull in the East Riding of Yorkshire and south of Perthshire in Scotland.
Residents in this region can also expect heavy showers throughout the afternoon and snow on high ground.
A yellow warning for wind, which could disrupt public transport and power lines, is also in place from 6pm on Wednesday, covering all of northern and central England, most of Wales and southern and central Scotland.
This warning is in force until 9pm on Friday, and expands to cover Northern Ireland from Thursday.
Met Office forecasters have said the conditions are caused by Storm Dudley which will move across the northern half of the nation from Wednesday night into Thursday morning, and Storm Eunice which follows.
In a Met Office daily forecast video, meteorologist Alex Deakin has warned people in the affected areas to brace for “heavy rain and ever-strengthening winds”.
“It’s going to be a windy day throughout with those winds continuing to pick up through the afternoon and the evening,” he said.
“There will be some snow on the hills across Scotland, but it’s the rain and more particularly the wind we’re concerned about in this storm system on Wednesday.
“It’s likely to cause transport disruption and dangerous conditions by the sea.”
Storm Dudley is expected to bring gusts of up to 80-90mph on exposed coasts and hills of Scotland, with 60-70mph possible further inland.
Meanwhile, Storm Eunice is predicted to bring heavy rain and possible snowfalls on high ground from the Midlands northwards.
Where snow does fall, the high winds are likely to create blizzard conditions, the Met Office has said.
Motorists have been urged to drive carefully, while electricity supply firms have issued warnings following the widespread outages in northern England and Scotland which followed storms earlier this year.