Most of England, all of Wales, and the west of Northern Ireland are covered by a yellow weather warning on Sunday, meaning heavy rain and thunderstorms will bring a chance of disruption to those areas.

Some areas could be battered by up to 30mm of rainfall in an hour, the Met Office said.

The west of Northern Ireland is also covered by a yellow weather warning on Saturday, meaning thunderstorms may cause flooding and disruption.

Motorists have been warned spray and sudden flooding could lead to difficult driving conditions and possible road closures.

Forecasters also warn flooding of homes and businesses "could happen quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds".

Delays are also expected on rail and bus services in the event of flooding or lightning.

The Met Office has said power cuts might occur and other services to some homes and businesses could be lost.

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Spokesperson Grahame Madge said: "There are risks of flash flooding associated with these forecast thunderstorms.

"Thunderstorms can unleash very intense rainfall and even hail.

"The impacts from this sudden release of precipitation can create local difficulties especially in urban areas as intense rainfall can lead flood waters to rise on roads, underpasses.

"This far out it isn't possible to forecast exactly where these systems will form but we are confident that some will experience intense conditions.

"We advise the public to follow the forecast and warnings so they can be prepared should thunderstorms develop at short notice."

Meanwhile, temperatures across the UK are largely set to exceed 20C (68F) over the weekend.

London is predicted to have highs of 24C and Cardiff 21C, while Glasgow at 23C is expected to experience heavy showers in the afternoon.

There will be lighter showers in Belfast with highs of 21C over the weekend.

No further weather warnings have been issued for next week.

This weekend's warnings come after a hosepipe ban was set to be introduced in Kent and Sussex as the country swelters during the current heatwave.

They also come after NHS chiefs warned the hot weather had contributed to "one of the busiest days on record" in Accident and Emergency departments on Thursday.

Charity Asthma + Lung UK added that the humidity had caused an "unseasonal spike" in asthma-related A&E visits and warned that thunderstorms over the weekend could cause "life-threatening" asthma attacks.