The Met Office has activated a ‘danger to life’ rain warning over southern England including London , with two inches of rain set to fall in a few hours tomorrow night.
Forecasters warned thundery showers could cause flooding, power cuts and travel chaos over a 12-hour period between 9pm tomorrow and 9am on Thursday.
The warning covers all of England south of Birmingham apart from Devon and Cornwall, while some of South Wales including Cardiff is also within the area.
The Met Office said 20mm (0.8in) to 40mm (1.6in) of rain is possible within one or two hours, with a ‘small chance of isolated accumulations’ over 50mm (2in).
Meanwhile parts of the West Midlands were on flood watch today – with the Environment Agency issuing six alerts – including for the River Blyth in Warwickshire; the Rivers Cole and Tame around Birmingham; and the River Stour in Staffordshire.
The Met Office warning for a 12-hour period between 9pm tomorrow and 9am on Thursday
A man with his dog at a deserted Portobello beach in Edinburgh during heavy rain yesterday
People hold umbrellas as they cross at Westminster Bridge in London in the rain yesterday
A woman shelters with an umbrella during rain on Wimbledon Common in London yesterday
Forecasters issuing the rain warning for tomorrow said ‘spray and sudden flooding could lead to difficult driving conditions and some road closures’.
They added that where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services.
The alert said that there is a ‘slight chance that power cuts could occur and other services to some homes and businesses could be lost’.
There is also a ‘small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.’
In addition, the warning said: ‘There is a small chance of fast flowing or deep floodwater causing danger to life.’
The Met Office said: ‘Whilst there is some uncertainty, and not all areas will be affected, scattered heavy showers on Wednesday evening may merge into longer spells of heavy, showery rain in places through Wednesday night into Thursday morning.
‘Where heavy downpours occur, perhaps thundery in places, accumulations of 20 to 40mm are possible in an hour or two, with the small chance of isolated accumulations over 50mm, potentially impacting the Thursday morning commute in some areas.’
It comes after forecasters warned thunderstorms are set to hit parts of the UK this week as the country is unlikely to ‘see the return of summer’.
A warning was also issued by the Met Office yesterday for up to 80mm (3.1in) of rain to fall over central and northern England, a large part of Scotland and all of Wales, which expired at midnight.
Showers continued into this morning, but conditions will be ‘a lot brighter and a lot more settled’ than yesterday with ‘sunnier spells’ across South West England, Wales and northern England and 23C (73F) highs, the weather service added.
The forecast for tomorrow is ‘sunshine and showers’, with most rainfall concentrated in England and Wales accompanied by a small chance of thunder and highs of 24C (75F) in the South East.
Parts of the West Midlands are on flood watch today – with the Environment Agency issuing six alerts (areas shown in amber on the map above), including for the River Blyth in Warwickshire
Conditions for the remainder of the week then look ‘unsettled’ with further outbreaks of rain and thunder in southern England looking likely, the Met Office said.
The warmest weather expected is on Friday with highs of up to 27C (81F) in England’s home counties, including Buckinghamshire and Oxfordshire.
Liam Eslick, meteorologist at the Met Office, said: ‘There could be quite a bit of change by the time we get to the latter part of the week – so it looks like it’s going to remain unsettled.
‘We’re not looking likely that we’ll see the return of summer as it’s now meteorological autumn as we’ve started September. We’re still seeing the effects of summer even though it is technically meteorological autumn.
‘We still have got that heat coming off the surface of the Earth, and with that warmer, more humid air coming off the continent as well – it’s not unusual that we see thunderstorms around this sort of time (of year).’
Average temperatures across the UK were just 14.37°C over June, July and August – 0.22°C below the long-term average
While the average temperature across the UK was low, the Met Office points out that there was some regional variation. England was just 0.07°C below average, while Scotland and Northern Ireland were 0.40°C and 0.45°C below average, respectively
It comes after the UK saw the coolest summer since 2015, bucking a trend of warm summers in recent years.
According to provisional Met Office statistics, the mean daily temperature (the average across 24 hours) was 14.37C – 0.22C below average.
But the forecaster pointed out that 14.37C would still be considered warmer than average if compared with 1961-1990, when the figure was 13.78C.
Met Office scientist Emma Carlisle said: ‘While this summer may have felt cool compared to recent years, it’s important to note where it sits in a historical context, with the changing climate of the UK increasing the frequency of warmer summers.’
According to the Met Office website, the meteorological seasons divide the year into four periods of three months to make it ‘easier’ to compare seasonal weather statistics.