Thunderstorms and heavy showers have struck parts of the UK, as forecasters warned of further unsettled weather over the coming days.

A weather warning for thunderstorms and heavy rain is in force across much of southern England and Wales.

The yellow warning, which covers all of Wales and south-west England, the Midlands and parts of south-east and northern England, came into effect at 1am and lasts until midnight on Sunday.

Cornwall has been the most affected area so far on Saturday.

Met Office meteorologist Becky Mitchell said: “The area we have seen most of the thunderstorms so far has been Cornwall, and there’s been some large hail reported there as well.”

Ms Mitchell added that the southwestern county has also seen lightning.

She warned there was “probably quite a lot of water on the road”, after reports of about 30mm of rainfall in the area, which could lead to “tricky driving conditions”.

“The only other place I’ve seen some thunder strikes was quite early this morning, about 6am, and that was in the Surrey and Oxfordshire region,” the meteorologist said.

Flooding in Cheltenham, Gloucestershire, near Lansdown Road after a thunderstorm in the area
A thunderstorm in Cheltenham on Friday caused flooding (Sophie Wills/PA)

She added: “We have got heavy showers across Wales and London at the moment too.

“We haven’t seen any thunderstorms with these showers yet but there’s still quite a while to go through the afternoon when we could potentially see some more.

“Typically as the afternoon goes on, we’ll see higher temperatures and the heat can help trigger the thunderstorms to kick off, so I expect through mid-afternoon we’ll see some more widespread ones.”

A map of highlighting the parts of England and Wales that are affected by the weather warning for September 21
(PA Graphics)

Further heavy, thundery showers, potentially accompanied by large hail, are expected across parts of Wales and southern England.

Some affected areas could see 50 to 80mm of rain.

Ms Mitchell said the weather is expected to remain “unsettled” over the next few days, with “potential for some localised flooding”.

A weather warning for rain will come into force on Sunday for Wales and central south-west England before another comes into effect on Monday, stretching to cover areas further east and further north as well.