A yellow thunderstorm warning has been issued for London on Wednesday, with forecasters predicting heavy showers and a risk of flooding in some areas. The Met Office expects a band of heavy showers and thunderstorms to hit the capital during the morning, with further storms possible in the afternoon.
Intense Rainfall and Flooding Risk
There is a chance of intense downpours, with 20-30mm of rainfall expected in less than an hour. In some areas, 40-50mm could fall within two to three hours, potentially leading to surface water flooding, the warning said. The warning is active from 3am to 10pm on Wednesday.
Many places will miss the showers, but others could see large hailstones and frequent lightning. The showers are expected to ease during the evening. Yellow flood warnings indicate a small chance that homes and businesses could experience flooding, which may lead to cancellations of public transport services and some road closures.
Impact of Dry Conditions
The hard ground following the sustained hot weather is expected to increase the risk of flash flooding. There is also a small risk of power cuts. The Met Office advises Londoners to check if their location is at risk of flash flooding and to consider preparing a flood plan if so. Those caught outside during thunderstorms are advised to find safe enclosed shelter, such as a car, and avoid sheltering under trees or other structures that might be struck by lightning.
The warning has a very low likelihood of happening but could have a medium impact on affected areas.
Affected Areas and Context
In addition to Greater London, other areas in the south east of England include Hampshire, Kent, Medway, Milton Keynes, Surrey, Reading, Windsor, and Buckinghamshire. Parts of the east of England, East Midlands, North West, South West, Wales, and the West Midlands could also be affected.
The rain follows one of London's driest summers on record. Millions of people were placed under hosepipe bans as London was declared to be in drought, while green spaces and parks across the capital were scorched by the heat. London also saw a spate of wildfires break out amid the dry conditions. For many, the rainfall will be a welcome reprieve to the scorching summer. Thunderstorms frequently happen after periods of hot weather when high temperatures warm up the ground and air, creating thunderstorm clouds that produce hail, thunder, and lightning.
