A Met Office weather warning has been issued for Northumberland on Friday, as heavy rain is expected to push northwards across England during the morning.
The rain is likely to be persistent and accompanied by hail and thunder in the south and east of England.
Rain will ease from the west during the evening, probably confined to eastern areas by the end of Friday.
Localised thunderstorms may develop during the afternoon, these potentially giving 15-25mm of rain in a few hours.
The warning is active in the south of England from 6am on Thursday (August 13) through until 11.50pm, and the rain is likely to be accompanied by thunder and lightning, with potential torrential downpours.
The Met Office is warning the public to be aware of a significant risk of very localised disruption to travel due to surface water flooding.
An area of low pressure is expected to develop just to the northwest of Spain tomorrow, heading north across Biscay towards the UK.
Around 15 to 30mm of rain is possible in 6 to 12 hours, with as much as 50mm possible very locally by the end of Thursday.