Severe thunderstorms may follow heatwave, Met Office warns

“Severe” thunderstorms and localised flooding may follow a heatwave across parts of Wales, the Met Office has warned.

The weather service said thunderstorms on Thursday could feature “frequent lightning, torrential downpours and large hail”, as it issued weather warnings.

Temperatures on Wednesday are expected to equal the hottest day of the year so far, as a heatwave spreads across the UK.

Daytime temperatures are forecast to reach highs of 30-32C in parts of eastern Wales and central and southern England.

The Met Office said “many more locations” would meet its heatwave criteria following Wednesday’s warm weather.

However, some areas could see as much as a month’s rainfall in a few hours on Thursday which could cause flooding, the weather service warned.

Yellow warning

The weather service has also issued a yellow thunderstorm warning covering much of Wales and England except the far South West and North West on Thursday from 1am until 11.59pm.

In a post on social media, the Met Office said the thunderstorms “may be severe on Thursday with frequent lightning, torrential downpours and large hail giving localised flooding”.

It added: “But the nature of these ‘hit and miss’ thunderstorms means that some of us will stay dry.”

The Met Office said it was “likely” that some weather warnings may need to be issued at short notice ahead of the development of the most intense thunderstorm activity.

Met Office spokesman Oli Claydon said a weather front approaching from the northwest on Friday would bring “fresher air and the end of the heat” – with lower temperatures expected by the weekend.