Power and other essential services, such as gas, water, mobile phone service could also be lost.
Neil Davies, Flood Duty Manager at the Environment Agency, said: “Isolated thunderstorms could bring sudden surface water and river flooding to parts of England today, which may lead to flooded properties and severe travel disruption in some areas.
“Further surface water and river flooding is also a possibility from Thursday to Sunday.
“Environment Agency teams are working hard alongside local authorities to reduce the risk of flooding and keep communities safe, clearing grills and weed screens in areas which may be affected by heavy showers, and are ready to respond and support where needed.
“We urge people to check their flood risk, sign up for free flood warnings and keep up to date with the latest situation at Gov.uk, call Floodline on 0345 988 1188 or follow @EnvAgency on Twitter for the latest flood updates.”