A yellow weather warning has been issued over Powys for a possible thunderstorm on Thursday, August 1.
The weather warning covers the majority of England and Wales.
Heavy showers and thunderstorms are expected to begin at 1am on Thursday and carry on throughout the day until 23.59pm.
The exact location of the showers is still unclear and some places will stay dry throughout the day.
Showers that do occur could be torrential with extra hazards of lightning, hail and strong winds possible.
A spokesperson for the Met Office said: “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.”
Spray and sudden flooding could lead to increased difficulty in driving and road closures are possible. There is a chance of power cuts to houses and businesses on Thursday with any adverse weather conditions that may occur. Bus services may be affected or delayed too. The Met Office’s warning impact matrix shows that the thunderstorm is unlikely to happen, but will have a fairly high impact should the poor weather conditions occur.
The weather warning area covers Brecon, Builth Wells, Llandrindod Wells, Rhayader, Presteigne, Knighton, Hay-on-Wye, Llanwrtyd Wells and Crickhowell.