A weather warning has been issued for the many parts of South, London, Surrey and the Southeast.
The yellow Met Office warning is in place from midday until 9pm today.
The warning says: “There is a small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.
“Spray and sudden flooding could lead to difficult driving conditions and some road closures.
“There is a small chance that some communities become cut off by flooded roads.
“Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services.
“There is a slight chance that power cuts could occur and other services to some homes and businesses could be lost.”