UK weather: Heatwave to give way to thunderstorms and hail

Met Office has warned some areas could see strong winds, lightning, thunder and hail

Meteorologists are warning that thunderstorms are set to roll in Wednesday evening across most of southern England and Wales, ending the nearly week-long heatwave.

The Met Office forecasts that the mercury will soar during the day in London and the south east, reaching a maximum temperature of 31C. If realised, this will mark the hottest day of the year, breaking Monday’s record of 28.6C set at London’s Heathrow Airport.

Met Office forecaster Steven Keates said: “There’s a chance that Wednesday could become the hottest day of the year.”

Adding that “three potential rounds of thunderstorms” could be expected, starting Wednesday evening and lasting until Saturday.

On Thursday, Met Office forecaster Clare Nasir said: “The thunderstorms are brewing across the Channel Isles and through Wednesday evening they will trundle their way northwards.

She warned of “heavy torrential downpours,” lightning, thunder, hail and “strong and gusty winds” associated with the storms.

The Met Office have issued yellow thunderstorm warnings for most of southern England and Wales, with the exception of parts of the west coast, starting around 6pm Wednesday and lasting until 9am Saturday morning.

They say that the thunderstorms could cause flooding and power outages in some areas, and that some communities could become cut off by flooded roads.

“Whilst not all locations will be affected, some intense thunderstorms may occur during this period with torrential rain, hail, frequent lightning and strong gusty winds possible.”

Between Wednesday evening and Friday morning, around 30mm of rain could fall within an hour, with the Met Office warning that some areas could potentially see 50mm over a period of 2 to 3 hours.

On Friday morning another spell of “thundery rain” is expected to push north across England and east Wales, with up to 60mm of rain falling over a 12-hour period

The Met Office expects that the storms will mostly clear into the North Sea on Saturday morning.