The Met Office has issued a 19-hour yellow weather warning for thunderstorms, covering London and 59 local authorities across England and Wales. The alert is in effect from 3am on Wednesday until 10pm, with a separate yellow warning issued for Thursday from 6am. Forecasters warn of heavy downpours, lightning strikes, and possible flash floods, with up to 50mm of rain expected to fall in just a few hours in the capital.
Warning details and affected areas
The yellow warning applies to 59 local authorities, including Greater London, and remains active from 3am to 10pm on Wednesday. An additional yellow warning has been issued for Thursday starting at 6am. The Met Office stated there is "a small risk of flooding and disruption from thunderstorms on Wednesday," advising residents to prepare for potential floods and disruption caused by lightning strikes.
In London, the risk of 'flash floods' is heightened, with up to 50mm of rainfall expected to arrive within a short period. The Met Office cautioned: "Homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes or hail. Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services."
Safety advice and precautions
British households have been advised to take precautions ahead of the storms and assemble an emergency flood kit, including essentials needed should a power cut occur. Regarding potential lightning strikes, the Met Office advises: "If you find yourself outside and hear thunder, protect yourself by finding a safe enclosed shelter (such as a car). Do not shelter under or near trees, or other structures which may be struck by lightning. If you are on an elevated area, move to lower ground."
Sadiq Khan has advised Londoners to ensure their "insurance covers flooding." The government also urged those in the capital to "put your valuables and important documents on a high shelf" and "learn how to turn off your water, gas and electricity supply."
Expected conditions and forecast
As well as Greater London, several other areas in the South East of England are expected to see downpours. Despite the wet conditions, warm temperatures are still forecast. The forecast for London on Wednesday says: "Cloudy start to Wednesday with heavy or thundery showers. Cloud lifts into the afternoon, bringing some brighter or sunny spells, although scattered heavy or thundery showers still possible. Feeling warm. Maximum temperature 27C."
