Nearly a month’s worth of rain is expected to lash parts of the UK in one day, prompting flood alerts to be issued in some regions.
The Met Office has issued a yellow weather warning for Wales, Northwest England and the Southwest ahead of heavy downpours on Friday.
Flooding on roads is likely to affect drivers and public transport and properties are also at risk of being swamped, forecasters said.
“There is a quite heavy burst of rain coming across Ireland and Northern Ireland and it will move across Scotland, Wales and England,“ said Met Office meteorologist Marco Petagna.
The yellow warning is in place between 8am and 10pm across an area stretching from the south coast of Cornwall to Burley.
The Environment Agency has issued three flood alerts as a result of heavy rain in the Lake District and Derbyshire.
Friday’s downpours may coincide with peak travel times during the afternoon and early evening, leading to difficult driving conditions on major routes, according to the Met Office.
Mr Petagna said up to 80mm of rain was possible in some areas, with higher ground likely to be soaked most. The average August rainfall is 107mm in Wales and 90mm in the Southwest.
Strong winds are also expected on Friday, with gusts of up to 40mph likely around exposed coasts and hills.
Mr Petagna added regions outside the warning area would not escape the rain and the whole of the UK would see rain at some point during the day.
“Much of England and Wales will see a fairly wet day,“ he said. “August actually can be a fairly wet month.“
The Met Office said the weekend would bring a mixture of sunshine and showers for much of the country, with thunderstorms and gales possible in the Northwest. Fine, dry weather is set to return by Tuesday.
