An amber weather warning is coming into force as dangerous thunderstorms prepare to batter the UK this weekend. The Met Office has warned that the storms could cause flooding and pose a danger to life in some areas.
Buildings could be damaged by floodwater, lightning strikes, hail or strong winds, forecasters said. Motorists have been urged to prepare for the severe conditions ahead.
Flooding danger to life
Heavy rain with thunder could create "fast flowing or deep floodwater, causing a danger to life" in the amber warning area. The warning spans the east and south east of England, including London, between 4am and 11am on Saturday.
Between 20mm and 40mm of rain could fall in one hour in the amber warning zone. Where heavy downpours persist, rainfall could reach 70mm to 100mm in just a few hours.
Significant surface water flooding
"Torrential rain, with thunderstorms in places, could lead to some significant surface water flooding during Saturday morning," the Met Office said. An ongoing deluge may cause "significant impacts" if it hits "more urban areas".
Homes and businesses are likely to flood and flooding could happen quickly, the Met Office warned. Some communities may be cut off if roads flood.
First amber warning since January
It is the first amber warning to be issued for London since January last year. The warning expands to most of England and some parts of southern Scotland from midnight to 9pm on Saturday.
Forecasters said these storms could "cause disruption in places". Areas of heavy rain with embedded thunderstorms will move north-westwards across a large swathe of central and eastern England through Friday night into Saturday.
Torrential rainfall expected
Rain will likely be torrential in places, bringing 20-30mm in less than an hour. In a few places, 60-90mm in two to three hours is possible, the Met Office said.
Frequent lightning and localised surface water flooding are also possible. Chief Met Office meteorologist Andy Page said intense rainfall will impact parts of the UK as thunderstorms move in from France.
Summer holiday disruption
"A range of severe weather warnings have been issued, including an amber warning covering south-east England and London," Page said. The intense rainfall could lead to surface water flooding as well as frequent lightning and hail.
This weekend is expected to be busy on the roads as more schools in England and Wales break up for the summer holidays. Page urged people to keep up to date with the very latest forecast as the situation evolves.
Temperatures remain low
The persistent cloud and rain will keep temperatures on Saturday relatively low. Maximum temperatures will mainly stay in the high teens to low 20Cs, but brighter spells in the south could reach the mid to high 20s.
The most recent amber warning issued for London was for wind on January 2 2024, during Storm Henk which swept through central parts of England and Wales. There will be spells of more pleasant weather in parts of the UK through the weekend, with some sunny spells between systems.
Drivers urged to prepare
The AA has urged drivers to prepare for disruption and take care on the roads. The breakdown service said this amount of rain is well over a month's worth for a normal July.
These storms could affect some of the popular holiday routes for early departures on this year's summer getaway. The potential for slippery road surfaces at junctions and roundabouts poses a hidden menace alongside the usual dangers of localised flash flooding and sudden surface water.
(PA) Note: This article has been edited with the help of Artificial Intelligence.
