Flood alerts have been issued for Somerset as a downpour of rain is expected following days of blistering heat.

Forecasters are predicting thunder, lightning and flooding as a yellow weather warning comes into force across the UK.

The Met Office has implemented the warning for Scotland and Northern Ireland until 11.59pm on Monday and 11.59pm for all of England and Wales on Tuesday after a change in air pressure led to dramatic showers.

Power cuts and delays and cancellations in trains and buses are predicted, while spray and sudden flooding could lead to difficult driving conditions for motorists.

Greg Dewhurst, a meteorologist at the Met Office, said the week would start off quite humid before cooling down later on.

He told the PA news agency: “We’ll start off initially quite humid, particularly across the south and the east of the UK, with thundery showers and sunny spells, but it will gradually become cooler and fresher as the week goes on.

“First half of the week, we’re looking at some heavy downpours and thunderstorms developing.”

Flood alerts in Somerset

A flood alert has been issued for the Somerset Coast at Porlock Weir by the Environment Agency with the rain set to arrive today.

They said: "The Flood Alerts will be in force for 2 hours before and after high water times.

"Areas most at risk include the low-lying roads and paths along the coastline between Gore Point and Hurlstone Point including Porlock Weir.

"We will continue to monitor levels closely."

The alert will be updated at midday today.