Parts of England could be hit by flash floods over the next 24 hours, the Environment Agency and Met Office has warned.
The agencies said a band of heavy, thundery rain was set to drench southern England and East Anglia from the early hours of Tuesday onwards, with some potentially torrential downpours.
The rain could lead to localised flooding from surface water on roads and land if drains become blocked or overwhelmed, and homes and businesses could be flooded overnight on Monday.
The south and east of England will be at risk of flash flooding from very early Tuesday morning through into the rush hour.
The Environment Agency said it was monitoring the situation closely and was encouraging local authorities and emergency services to prepare for the possibility of surface water flooding.
Local authorities should ensure drains are clear and prepare for disruption as a result of flooding.
Met Office spokeswoman Sarah Holland said on Monday: "There's some heavy rain and showers due to spread into southern counties overnight and into tomorrow morning.
"Some of these could be thundery at times. Although we're not expecting a tremendous amount of rainfall, there's been so much rain around recently we could see some surface water flooding."
She said the band of rain would last from the early hours through to Tuesday lunchtime and would also affect the Midlands.
Last week parts of the south coast were hit by floods after heavy downpours, with Portland in Dorset receiving almost the monthly average rainfall in just nine hours. Vehicles were damaged, roads closed, and in Bournemouth, parts of the town centre were closed, including one street where a wall collapsed and ruptured a gas main, causing homes and businesses to be evacuated.
