UK weather forecast: Streets turn to rivers as Britain is hammered by thunderstorms

Britons have been warned to prepare a ‘grab bag’ of essentials in case of flooding as torrential rain and thunderstorms hammer parts of the country today, causing mudslides while deluging rail lines and streets.

Firefighters said people should prepare a flood kit, with those living in basement flats or low-lying properties particularly at risk as the heatwave ends with a bang – and up to two inches of rain falling in three hours today.

The worst of the flash floods so far have been seen in staycation hotspots across South West England such as Cornwall, Devon and Somerset, where hundreds of thousands of families are on their summer holidays. 

The A358 in Somerset was closed at Combe Florey after a mudslide last night which saw workers remove more than 50 tonnes of mud and potatoes – and it was still shut this afternoon due to the amount of debris. Diversions were put in place, and council workers joked they were ‘working hard to ensure no chips on drivers’ windscreens’.

Families braced themselves for traffic chaos and power cuts as forecasters warned of dangerous flash floods – while authorities told people to prepare the emergency bag of vital belongings in case their homes are damaged.

The National Flood Forum said a flooding ‘grab bag’ should contain insurance and other important documents, mobile phones and chargers, emergency cash and credit cards, and any medication or prescription forms.

The London Fire Brigade said people should be ‘prepared and know what to do should a flood occur’ and ‘use sandbags to limit the water flow and move belongings to a higher level’. The Met Office said people living in ‘low-lying properties’ should make sure their valuable items are ‘ready to go’, or ‘on a higher level of your house’.

The guidance will apply to millions of people – with Environment Agency the estimating that 5.2million homes in England, or one in six properties, are at risk of flooding. This includes 2.4million at risk from rivers and the sea, 1million of these also susceptible to surface water flooding and a further 2.8million at risk of surface water alone. 

Dramatic videos showed fast-flowing floodwater cascading down steep roads and deluging junctions in Devon and Cornwall – while Londoners hid under trees, blankets and bin lids to avoid sudden bouts of torrential rail. 

But while the heatwave has now technically ended after eight days today, it remains very warm in much of the UK with highs of 27C (81F) expected this afternoon, before 25C (77F) tomorrow and Thursday, and 24C (75F) on Friday.

The whole of England and Wales has been put under a thunderstorm warning for today, with a separate rain alert in place for Scotland. There is also a further thunderstorm warning covering all of southern England tomorrow.

The Met Office said some places will stay dry today, but others will see thunderstorms with torrential rain – and flooding could happen quickly, with damage to buildings from water, lightning strikes, hail or strong winds.

Forecasters said fast ‘flowing or deep floodwater is possible, causing a danger to life’ and that the conditions could cause delays to trains and along with difficult driving conditions as well as some road closures.

Speed restrictions were imposed on some rail routes in Scotland today due to the heavy rain – with train services affected between Glasgow and Inverness, Perth, Dundee and Aberdeen. Flooding was also seen near Perth. 

The Met Office said thunderstorms and areas of heavy rain will develop quite widely across much of England and Wales throughout today, and the extent of these thunderstorms will be more widespread than yesterday.

Up to 1.2in (30mm) of rain is possible within an hour, but where areas of thundery rain become slow-moving, some places could see 2in (50mm) in less than three hours – and even higher totals in a few spots over the whole day.

The stormy weather comes after weeks of soaring temperatures – with at least 30C (86F) recorded for eight days in a row up to and including yesterday, and an unprecedented 40.3C (104.5F) last month. The official heatwave threshold varies around the country, but for London it is three consecutive days of 28C (82F) temperatures.

Meanwhile experts warned that the drought is far from over as the country needs weeks of rainfall to replenish supplies. It comes after the country’s driest July on record and the driest first half of the year since 1976.

Christine Colvin, from the Rivers Trust, warned there is a risk that people will not take the drought seriously in the coming days, adding: ‘We want people to keep this rainfall event in context and as part of the bigger picture.

‘The bigger picture is that we’ve actually still had an incredibly dry year as well as a dry summer and it’s going to take sustained rainfall to replenish our supplies. Just because it rains, it doesn’t mean the drought is over.’

She added: ‘It’s going to take sustained rain to replenish the supplies we actually use, which are the aquifers and the managed storage in our reservoirs.’

The Environment Agency had ten flood alerts in place for England today, including two on the north Norfolk coast, four in Derbyshire, three in Nottinghamshire and another in Leicestershire. 

There were also 16 flood alerts from the Scottish Environment Protection Agency, covering the likes of Aberdeenshire, Skye and the Scottish Borders.

The heavy downpours over a short period will not soak into the earth – baked almost as hard as concrete by the heat – and are instead flooding streets in towns and cities. 

The Met Office warned that people who live in ‘low-lying properties’ should make sure their valuable items are ‘ready to go’, or ‘on a higher level of your house’, due to the current high flood risk.

Speaking to Sky News this morning, Met Office meteorologist Clare Nasir said: ‘For low-lying properties, which perhaps have been built on a floodplain, yes, there is a risk of flooding in properties.

‘Get all your documents, whether it’s your mobile phone, your passport, etc, all those things you don’t want to be damaged by floodwater and make sure they’re ready to go or on a higher level of your house’.

She added that the downpours overnight and into this morning are ‘the wrong kind of rain which we need for the ground’, as the ground is too hard to absorb it.

‘What we’re looking for is sort of continuous rain, moderate rain, rather than this incredibly intense burst, which currently is moving up across more southern areas of England. So we’re not out of the woods yet.’

And London Mayor Sadiq Khan said: ‘I have written to tens of thousands of Londoners who live in homes that could be affected by flash flooding. 

‘My message to Londoners is to please contact Floodline, go to your local authority’s website to see what you can do to reduce the chances of you being flooded and also to minimise the consequences on you.’

Referencing flash floods last July – when two months’ worth of rain fell in two hours – he added: ‘We learned a lot from last year [when] people’s homes, businesses and public transport were flooded.’

Patrick Goulbourne, the London Fire Brigade’s Assistant Commissioner, added: ‘It is really important that Londoners – particularly those living in basement properties – are prepared and know what to do should a flood occur.

‘Pay attention to weather alerts and prepare a flood kit or grab bag. People can use sandbags to limit the water flow and move belongings to a higher level.’

A flooding ‘grab bag’ should contain insurance and other important documents, mobile phones and chargers, emergency cash, and any medication, according to the National Flood Forum charity.

For parents with young children, it should also include nappies, a favourite toy, clothing, wipes, milk and baby food.

In Cornwall yesterday, motorists battled their way through flooded roads including in Truro, while shoppers in the North West prepared for up to two inches of rain. Another video showed floodwater running down a steep street in the Devon village of Clovelly.

In Dorset – which saw thousands of sunseekers on the seafront over the weekend – beaches were almost deserted.

The National Flood Forum warned today that the UK is still ‘reactive and not proactive’ about flood risk even though flooding has become a ‘regular pattern’ for the country,

Speaking to Nick Ferarri on LBC this morning, Heather Shepherd said: ‘Flooding has definitely increased and certainly the length of time that I’ve been working in flood risk, and we see it now as a regular pattern, don’t we, every year.’

However, she added: ‘I still think we are quite reactive and not proactive. As soon as it’s not in the headlines, flooding, we tend to be a bit too laid back.’

Ms Shepherd expressed concern about the Government’s ‘cost criteria’ regarding the accessibility of funding for flooded communities, saying: ‘There are people, particularly in rural and deprived areas, that repeatedly are flooded and can’t access any funding to do anything about that.’

She also warned that ‘building like mad everywhere’ was increasing flood risk, as ‘a lot of that is on places where water had space and it no longer has. It overwhelms our drainage infrastructure. And we’re seeing more and more urban flooding’.

Last week a drought was declared in eight areas of England including Devon and Cornwall, Kent and south London.

Several water firms – including Welsh Water, Southern Water and South East Water – have already imposed hosepipe bans to tackle the shortage.

South West Water was the latest company to announce restrictions in Cornwall which will kick in on August 23.

Yorkshire Water’s ban will start on August 26 and Thames Water has said it is planning one but has not confirmed the date.

A £1,000 fine could be imposed on anyone who breaks the ban but water companies have not said if they have pressed for prosecutions in the past. 

Met Office spokesman Stephen Dixon said that thunderstorms and heavy rain is likely to hit parts of Scotland as well as areas of the South West and East of England.

He added that up to two inches of rainfall – almost a month’s worth of rain – could fall in just three hours in some parts.

He added: ‘That being said, it is quite hard to pinpoint exactly where these thunderstorms will crop up. Some areas will miss the showers completely.

‘But, where they do come down, there could be some impacts like surface water flooding – with the rain obviously hitting dry land –travel disruption and power cuts affecting homes and businesses.’

And Met Office meteorologist Greg Dewhurst said: ‘Temperatures will be lower, looking at highs of around 27C as a maximum temperature, but it will still be on the humid side (today).

‘Thundery showers across central and southern parts of England on Wednesday and temperatures will be around 26C as a maximum.’

Mr Dewhurst warned that the bad weather conditions could pose difficulties for those hoping to travel and urged people to stay up to date with developments in their local area.

‘We’ll see some very heavy showers develop over the coming days, hail, frequent lightning, some flash flooding is possible like we’ve seen in places today so our advice is to stay tuned to latest forecasts and local radio stations as well, to get the latest information,’ he said.

‘It is worth being aware that there could be disruptions or delays to travel.’

He added: ‘It will be in turns fairly breezy as we end the week, with some showery rain, particularly across the north of the UK, so temperatures generally around average for many but could possibly be a bit above for the far south, which is the mid-20s.

‘It looks probably most likely from late Wednesday to Thursday onwards it will become fresher for everyone.’

Professor Hannah Cloke, an expert in hydrology at the University of Reading, warned that the parched soil increased the risk of ‘dangerous’ flooding.

She said: ‘The ground is really dry and when it is so dry it acts a little bit like concrete and that water can’t get in so it drains straight off. There is the damage to homes and businesses these floods can cause, and inconvenience with transport disruptions –but if it is very heavy in one place it can also be very dangerous.’

On how it could affect cities like London, she said: ‘If you get heavy rain in a city, the drainage system can cope up to a point. But if there is really heavy rain it can overwhelm the system – the rain cannot run away quick enough.

‘Water tends to find the lowest pathway – that is why it is so dangerous for cities with these surface area floods. That is why it is of concern to the Tube and underground car parks and things like that.’

‘If we are in London and the parks are really, really dry, there is nowhere for the water to run so it is exacerbating the risks we already have in cities.’

In rural areas, Professor Cloke said flooding often hits low points in roads and under bridges.

Also today, Ofwat chief executive David Black has defended targets set for water companies as ‘challenging but achievable’.

Speaking to BBC Radio 4’s Today programme and asked if the targets set for leaks are tough enough, Mr Black said: ‘Yes, we set challenging but achievable targets for water companies, leakage being one of them.

‘So at the last price review we challenged the sector to reduce leakage by 16 per cent and the latest information we have shows that 13 out of 17 companies (are) on track to deliver that in the first two years.’

He added: ‘I can point elsewhere in the (targets) regime where fewer companies are succeeding, so for example on pollution incidence less companies are successful.

‘So we have set challenging targets and in fact at the last price review four out of 17 companies appealed our determination. So they thought the determination was too tough, and one of their contentions was that the targets were too challenging.’

Mr Black also said that overall, the water supplier sector ‘has underperformed against the price review’.

He told the BBC: ‘Where companies are falling short on leakage they will incur penalties on that. It may be that they are outperforming the regime elsewhere. But overall the sector as a whole has underperformed against the price review thus far into the period.’

Mr Black added: ‘So far to date the sector hasn’t succeeded in earning the – if you like – these standard rates of return.’

He said: ‘We certainly agree that customers should get better service and expect better service and that’s why we have set performance targets that aim in every case to drive better performance from companies.

‘There are some companies like Thames Water which have been repeated poor performers and we have taken action against them and other companies.’

Asked if he thinks there is nothing wrong with the system, Mr Black said: ‘No, I think that companies like Thames and Southern really need to up their game. I think it’s very concerning that other companies that may be performing better in the sector it casts a long shadow when we see poor performance.’