The Met Office has issued a storm warning for thundery weather to hit Devon this weekend.
A yellow warning of severe weather is in place for the whole of Saturday.
a spokesman said: "Thundery downpours are expected to affect parts of England, Wales and southern counties of Scotland during Saturday.
"The public should be aware of the potential for localised flooding due to the intensity of these storms, although at this stage the location of the heaviest rainfall is uncertain.
"Warm, humid air is likely to be pulled northwards from France late on Friday and during Saturday.
"Within this airmass, there is an increasing likelihood that heavy, thundery showers will break out.
"It is likely that many places within the current broad warning area will miss the worst of the storms; over the next few days it may be possible to focus on the areas most at risk."
