Thunderstorms, lightning and heavy rain are forecast to hit parts of Britain this weekend, with flooding expected to cause travel chaos.
The Met Office has issued a yellow thunderstorm warning for large areas of England and Wales for the next three days.
The extreme weather may damage buildings and cause power cuts and cancellations to train and bus services, while flooding could cause roads to close.
The South of England and Wales are likely to have the most rainfall, with frequent lightning, gusty winds and heavy downpours with 30 to 40mm of rain possible in less than an hour, according to the Met Office.
Five flood alert warnings have been issued across the West Midlands by the Environment Agency.
Met Office forecaster Matthew Box said: “Saturday will begin mostly cloudy for most areas across the UK but as the day goes on showers will start to break out in the South and South East of England.
“As the day progresses further there’s a chance of some rumbles of thunder and potentially some hail and lightning.
“The risk of thunder will start to push further north on Sunday, with central parts of England and Wales facing heavy rain and the chance of flooding.”
However, areas in Scotland and north-western England and Northern Ireland are forecast to be dry with a few sunny spells after a week of heavy rain.
Mr Box said this was due to winds causing an “East-West” split in northern areas.
Chief Meteorologist Frank Saunders added: “Up until Monday, thunderstorm warnings cover much of England and Wales, with parts of southern England and South Wales seeing the greatest likelihood of impacts.”
Due to the continuing hot weather, large parts of the UK will be at risk of thunderstorms, Mr Saunders explained.
Neil Davies, Flood Duty Manager at the Environment Agency, said: “Isolated thunderstorms could bring sudden surface-water and river flooding, which may lead to flooded properties and severe travel disruption in some areas. Further surface water and river flooding is also a possibility until Sunday.
On Monday, northern Scotland is expected to be sunny, while showers are forecast in the East.
Elsewhere, there will be sunny intervals, showers or thunderstorms.
Tuesday will see sunshine and showers, with rainfall particularly heavy in the North, while Wednesday is forecast to be drier in the South with showers further north.