Thunderstorm warnings have been issued across south-west England and parts of Northern Ireland for Tuesday that could continue into the evening.
The Met Office also said “intense” downpours, with up to 2in (5cm) of rain, could be expected to fall over a few hours in Cornwall, Devon, Dorset, Plymouth, Somerset, Torbay and in western parts of Northern Ireland.
Frequent lightning strikes and hail may also be seen, its yellow thunderstorm warnings said. Both warnings are in place until 9pm on Tuesday.
On Saturday, warnings of thunderstorms across England and Wales were followed by bad weather in a number of regions, with dozens of lightning strikes being recorded in Powys throughout the afternoon.
As part of the latest announcement, a yellow weather warning is also in place between 1pm and 8pm on Tuesday, covering large parts of Wales and south-west England. It means sudden flooding could occur in the affected areas, as well as slow-moving heavy showers, causing disruption to transport and roads.
People have been told to expect possible spray and sudden flooding, which may cause power cuts, transport cancellations and damage to buildings.
Amy Bokota, a Met Office forecaster, said: “The downpours could be slow moving, and that’s the main trouble. The wind’s quite light at the moment so when they do form, they could be quite slow moving and intense.”
She added: “Where you see them they could be quite intense and dramatic, but not everywhere’s going to see them and some places just down the road could be completely fine and shower and thunderstorm-free.”
