A yellow weather warning has been issued for south Wales with thunderstorms set to hit the area on Thursday (August 1).

The Met Office issued a yellow weather warning due to heavy showers and thunderstorms which will be in place across most of south Wales from 12pm to 11.59pm on Thursday.

The heavy showers and thunderstorms are likely to cause flooding, travel disruptions, loss of power and pose a danger to life, according to the Met Office.

The weather warning will affect most of South Wales including Newport, Blaenau Gwent, Monmouthshire, Caerphilly, Cardiff and Vale of Glamorgan. 

These thunderstorms will follow some warmer weather, with temperatures set to reach highs of 28 degrees in some areas of south Wales on Monday, Tuesday and Wednesday (July 29, 30 and 31).

What to expect from the yellow weather warning in South Wales

The Met Office said the yellow weather warning was issued across South Wales due to heavy showers and thunderstorms that are expected to develop on Thursday and may cause some disruptions.

The thunderstorms associated with the yellow weather warning are also set to cause:

  • Difficult driving conditions and some road closures due to spray and sudden flooding
  • Chance of delays and some cancellations to train and bus services as a result of flooding or lightning strikes
  • Power cuts and disruptions to other services in homes and businesses
  • Homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds
  • Fast flowing or deep floodwater could cause danger to life

A Met Office spokesperson added: "Heavy showers and thunderstorms are likely to break out across parts of England and Wales on Thursday afternoon.

"The exact location of showers is still uncertain and some places will stay dry all day.

"However, where the showers do occur they could be torrential, with the additional hazards of lightning, hail and gusty winds.

"The heaviest showers could result in 20-30 mm within an hour, with 24 hour accumulations possibly reaching as much as 70-90 mm where multiple showers affect the same location."

Everywhere in Wales set to be affected by yellow weather warning

Areas of Wales set to be impacted by the yellow weather warning issued by the Met Office are:

  • Blaenau Gwent
  • Bridgend
  • Caerphilly
  • Cardiff
  • Denbighshire
  • Flintshire
  • Merthyr Tydfil
  • Monmouthshire
  • Neath Port Talbot
  • Newport
  • Powys
  • Rhondda Cynon Taf
  • Torfaen
  • Vale of Glamorgan
  • Wrexham

See exactly where in South Wales this yellow weather warning will be in place.See exactly where in South Wales this yellow weather warning will be in place. (Image: Met Office)

How to prepare for the yellow weather warning and thunderstorms in South Wales

The Met Office has issued advice on how to prepare for the yellow weather warning and the risks it poses.

A Met Office spokesperson said: "Consider if your location is at risk of flash flooding. If so, consider preparing a flood plan and an emergency flood kit.

"Prepare to protect your property and people from injury.

"Before gusty winds arrive, check to ensure moveable objects or temporary structures are well secured. Items include; bins, garden furniture, trampolines, tents, gazebos, sheds, and fences.

"Give yourself the best chance of avoiding delays by checking road conditions if driving, or bus and train timetables, amending your travel plans if necessary.

"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.

"If you find yourself outside and hear thunder, protect yourself by finding a safe enclosed shelter (such as a car).

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"Do not shelter under or near trees, or other structures which may be struck by lightning. If you are on an elevated area move to lower ground.

"Be prepared for weather warnings to change quickly: when a weather warning is issued, the Met Office recommends staying up to date with the weather forecast in your area."

The yellow weather warning will be in place across South Wales from 12pm to 11.59pm on Thursday, August 1.