Warnings of thunderstorms and heavy rain remain in place for large swathes of the UK after scorching temperatures were recorded for the sixth day in a row in parts of southern England.

The Met Office upgraded its thunderstorm warning to amber for much of Wales, the West Midlands and parts of the North West on Wednesday evening after severe storms caused disruption in some areas.

It warned that flash flooding, hail and strong winds could suddenly occur, while buildings could be damaged and power could be lost in some communities, with the warning in place until midnight.

WEATHER Hot
(PA Graphics)

Meanwhile, a yellow thunderstorm warning covers much of England and Wales due to unsettled conditions caused by the current heatwave.

It comes as water firms advised customers in certain areas to restrict their water usage amid sweltering conditions.

Thames Water said that ongoing power supply issues in Guildford meant it was using tankers to bring water into the area, as it urged customers to use water for essential purposes only in the coming days.

Essex and Suffolk Water said that due to “record water demand” it was working to maintain supplies but users could notice lower than normal pressure.

Temperatures reached 34.6C (94F) in St James’s Park in central London on Wednesday, marking the first time since at least 1961 that there had been six consecutive days of 34C and above.

It was also the third day in a row of the mercury hitting 35C (95F) or above, with Wednesday’s highest temperature of 35.4C (95.7F) recorded at Heathrow, according to the Met Office.

Forecaster Greg Dewhurst said: “It’s not often we get temperatures this high over several days, and that is triggering thunderstorms across parts of England and Wales.

“If rain is falling on places that have been quite hot and dry, and the ground is quite hard, the rain doesn’t have anywhere to go, and from that we can see flash flooding.”

Gloucestershire Fire & Rescue Service said it was experiencing “high call volumes” due to bad weather and had been made aware of flash flooding in Gloucester on Wednesday evening.

“Whilst the bad weather continues, please be careful and only travel if absolutely necessary and with extreme caution,” it tweeted.

Elsewhere, Cheshire Police said on Twitter they were dealing with a number of weather-related incidents in the village of Tarporley, including fallen trees and flash flooding, and advised nearby residents to avoid all but essential travel.

Some 10 flood alerts covering areas in the West Midlands were issued by the Environment Agency on Wednesday evening, while three flood warnings are in place – meaning immediate action is required.

Two of the warnings, which indicate flooding is expected, cover the River Trent, while third was issued for Sandyford Brook in Stafford.

Severe storms could see 30 to 40mm of rain falling in less than an hour in some places, which comes after heavy downpours lashed large parts of Scotland and caused flooding on Tuesday evening.

Flooding in Stonehaven, Aberdeenshire, in Scotland
Flooding in Stonehaven, Aberdeenshire, in Scotland (Martin Anderson/PA)

Three people died in a train derailment in Aberdeenshire after a ScotRail service crashed on Wednesday amid heavy rain and flooding.

British Transport Police (BTP) said those pronounced dead at the scene near Stonehaven included the train’s driver, while six people were injured in the derailment.

Thunderstorms are expected to clear overnight, while temperatures could remain above 20C (68F) for “warm and humid” conditions, according to Mr Dewhurst.

Summer weather Aug 12th 2020
Paddleboarders enjoy the hot weather in the Isle of Dogs, east London (Stefan Rousseau/PA)

Following a grey start to Thursday, there will be sunny spells across much of the country with maximum temperatures of up to 32C (90F) in the south east of England.

“It’s still going to be warm and humid and that could then trigger some thunderstorms across parts of England and Wales through the afternoon and evening tomorrow,” he said.

A yellow thunderstorm warning which covers the majority of England, excluding parts of the north-east, has been issued by the Met Office for Thursday.

Further unsettled weather is predicted throughout the afternoon and evening.

Mr Dewhurst added: “Generally, the rest of the week remains unsettled with showers, some of them thundery and heavy, but there will still be some warm, sunny spells at times too.”