DORSET is being warned to prepare for thunderstorms after a weather warning was issued for the south west – with fears 40mm of rain could fall in three hours.

The Met Office has warned of possible disruption across the county, as well as Wiltshire and Somerset, tomorrow and Saturday (September 20 and 21).

“While many places will remain dry, thunderstorms and heavy showers could cause some disruption on Friday in a few places,” a forecaster said.

They warned of “some damage to a few buildings and structures from lightning strikes”, as well as difficult driving conditions.

“A few thundery showers may be present across southern and south east England early on Friday, but from the middle of the day they are expected to develop more widely within the warning area,” they added.

“While some places will remain dry, where thundery showers do occur, they will bring frequent lightning, gusty winds, potentially some large hail, as well as brief spells of heavy rain.”

They said between 15mm and 25mm of rain may fall in an hour, with a “very small chance” of that rising to 30mm to 40mm in three hours in the south west.

“Showers will tend to ease and fade during Friday evening,” they added.