Some people will have a stash of batteries somewhere at home for the odd time that something needs fixing or replacing. But the Met Office has urged millions of people to stock up and be prepared after issuing a yellow weather warning for large parts of England and Wales.

On top of heatwave temperatures, people have been warned that there is a chance of 'scattered thunderstorms' from Saturday, June 21, through to the early hours of Sunday, June 22. With thunderstorms, there is a chance of "frequent lightning" as well as gusty winds, heavy downpours and the risk of power cuts.

As such, the Met Office is urging households to prepare for a potential loss of power by ensuring they have a few key supplies on hand should the worst happen. The website states: "People cope better with power cuts when they have prepared for them in advance. It’s easy to do—consider gathering torches and batteries, a mobile phone power pack, and other essential items."

The warning is set to come into effect from 3pm on Saturday afternoon. The warning should be lifted by 4am on Sunday morning. The Met Office claims that thunderstorms can occur at any time of the year but, thankfully, they can often pass quickly.

They said: "It is during the summer months when thunderstorms in the UK are most likely to produce large hail, gusty winds and torrential downpours that can cause disruption to transport networks and damage property." More information is available online.

On its website, the Met Office has advice for households on how to prepare for power cuts. The experts advise:

• If electricity is crucial for any medical equipment you have, please contact your Distribution Network Operator (DNO) at any time as they may be able to put you on their Priority Register (see below) for assistance during any power outage
• Make sure you have multiple torches along with extra batteries
• Make sure you keep your mobile phone charged so you can make calls in case of an emergency
• Keep fridges and freezers closed, with a blanket over as they will stay cold for many hours
• Keep important documents safe and handy
• Look out for elderly neighbours and ensure they are prepared for a possible power cut
• Switch off appliances - turn off items such as irons, ovens, electric fires and fryers as they could pose a hazard if the power comes back on when you are not there
• For people using a digital landline who don't have a mobile phone, or who live in an area with poor/no mobile signal, speak to your communications provider about additional support they can offer you in advance

According to the Met Office warning, the following areas have been blanketed with the same yellow warning (as of Friday, June 20). People should keep an eye on the Met Office website and social media in case this changes.