THUNDERY downpours could result in road closures this bank holiday weekend, the Met Office has warned.

A yellow 'be aware' warning has been issued for Wiltshire, Swindon, Gloucestershire, Bath and North East Somerset, Bristol, Dorset and Somerset from 11am on Saturday until 9am on Sunday.

The Met Office says thundery showers are likely to move northwards into some southern parts of England during Saturday morning, becoming more widespread and heavy through the course of Saturday and overnight into Sunday morning.

"Please be aware of the risk of local disruption to transport and outdoor activities," said a spokesman.

"In particular, be aware of the potential for some spray and standing water on roads, and the possibility of road closures."

The chief forecaster said: "A frontal zone associated with very warm and moist air will move northwards during Saturday. It will become slow moving over central areas of England and Wales later Saturday, persisting overnight, before slowly easing away to the east during the course of Sunday morning.

"There remains a lot of uncertainty in where the heaviest and most prolonged thundery showers will occur, with some places in the warning area having only small amounts of rain. 

"However, there is a risk of some locally large rainfall totals, with 25 to 50mm (1-2ins) of rain possible in places."

The forecast for Monday is cloudy with a few showers, particularly in the west.