UK heatwave: what caused it, the impact on the countryside and what's next for the forecast?

TV weather presenters and meteorologists John Hammond and Sara Thornton offer insight into the current UK heatwave, looking at the impact it has had on the countryside and predict what's next for the forecast

6th August 2018
dried river

UK heatwave – the talk of town and country

The weather might be the nation’s favourite conversation, but during this phenomenal year, it is all people have been talking about.

It has been a summer that has divided us. For many, especially sun-loving holiday makers, the heatwave has been a godsend after several mediocre years. Most of us,­­­ haven’t even had to mow the lawn! But as the landscape has become evermore parched, it’s been an endless, overheated headache for those at the sharp end of heath-fires, hosepipe bans, wilting crops and dwindling livestock feed. Now even some trees are showing the strain.

High and dry – just like 1976?

Reaching for the record books, the heat and sunshine this summer has often been of similar intensity to 1976. The common denominator is a dome of high pressure, blocking our usual conveyor belt of moist and mild Atlantic weather. But broadbrush statements don’t paint the whole picture. For some corners of the UK, this year may have been even more extreme - the driest start to summer for well over 50 years. On the other hand,1976 saw an extraordinary 18 days running when somewhere in the UK had temperatures above 30C. This year we haven’t got out of single figures.

8th September 1976: A public information notice warning about the drought, erected by the road in the Bridport area of Dorset/Credit: Getty
8th September 1976: A public information notice warning about the drought, erected by the road in the Bridport area of Dorset/Credit: Getty

But there’s one key factor which made the summer of 1976 more impactful. Back then, the UK had lacked rain for over a year. When the heatwave struck, the country was already thirsty. Serious water shortages then ensued, with hundreds of livestock perishing as fodder reserves became exhausted. Dessicated crops withered before farmers’ eyes, spawning panic buying of vegetables as shop prices soared.

Great Drought of 1976: what happened and what was the impact on Britain?

The Great Storm of 1987: what happened and how did it change weather forecasting?

Climate Change - fanning the flames of attribution

Since 1976 since there hasn’t been a significant rise in the frequency of UK ‘heatwave’ summers. It’s been a lucky break! The ‘slow-burning’ long-term trends are often disguised by the shorter-term ‘noise’ that makes up our variable weather. It’s a tangled web.

he dried up bed of Yarrow Reservoir near Bolton as the heatwave continues across the UK on July 23, 2018 in Bolton, England. A hosepipe ban in the North West of England will come in to force on August 5th as the reservoirs serving millions of customers become depleted
The dried up bed of Yarrow Reservoir near Bolton as the heatwave continues across the UK on July 23, 2018 in Bolton, England. A hosepipe ban in the North West of England will come in to force on August 5th as the reservoirs serving millions of customers become depleted/Credit: Getty

But many leading scientists suggest that deadly summer heatwaves and droughts will become the norm within a few decades. And although millions of pounds have been spent to improve water supplies and repair leaks, the booming population and ever-increasing demands from industry foretell a high-stakes race ahead between supply and demand.

What caused the UK heatwave?

2018 has already seen its fair share of severe weather, with the ‘Beast from the East’ hitting our shores earlier this year.  It seems we’ve lurched from one extreme to the other, with very little ‘normal stuff’ in between.

A tractor fitted with a front snow-plough, helps to clear snow on the A606 Stamford Road at Empingham in Rutland, between Stamford and Oakham, during the 'Beast from the East' bout of cold weather that hit Britain during late February/early March 2018.
A tractor fitted with a front snow-plough, helps to clear snow on the A606 Stamford Road at Empingham in Rutland, between Stamford and Oakham, during the 'Beast from the East' bout of cold weather that hit Britain during late February/early March 2018/Credit: Getty

Odd things started happening back in February. It was a sudden warming way up in the stratosphere that sent winds across the whole northern hemisphere spinning into reverse –  from the top to the bottom of the atmosphere. Thanks to the ‘Beast from the East’, extreme cold and historic blizzards paralysed the country. Children rejoiced as schools were closed on the coldest March day on record. But the atmospheric aftershocks have lingered on, long since the last snowdrifts melted.

Blowing hot and cold

Our normal Atlantic westerlies have gone ‘AWOL’. Instead, continental easterlies have become commonplace. While landmasses cool down much more quickly in winter, they warm up more dramatically in summer than do oceans.

And as the continent heated up, the same winds that brought such bitter cold late winter weather began to deliver blowtorch heat in spring and summer. Ever since April, the UK has basked in successive months of above normal temperatures.

Dry parched park in Wimbledon London caused by the heatwave and hot weather
Dry parched park in Wimbledon, London caused by the heatwave and hot weather/Credit: Getty

It’s thought that sea temperature patterns in the Atlantic have helped this self-sustaining force-field. ’Hot and Dry’ has bred yet more ‘Hot and Dry’.

What's next for the weather forecast?

So will the continental ‘block’ keep our mild, damp westerlies at bay through the rest of the year; or will the atmospheric damn suddenly burst? In 1976, once it started raining in late August, it barely stopped until Christmas. While there are no clear signs of a lasting deluge yet as autumn approaches, and the continent cools again, the prospect looms that, come winter, we’ll be lurching back into the freezer unless the westerlies rediscover their ‘mojo’.

Weather, eh - never a dull moment. Come what may, it will continue to give us plenty to talk about through the rest of the year. That’s our forecast!

weathertrending

John Hammond and Sara Thornton
Meteorologists and presenters John Hammond and Sara Thornton

With nearly 40 years of weather broadcasting expertise between them, meteorologists and presenters Sara Thornton and John Hammond love talking about weather - extreme or otherwise! At weathertrending.com and on social media @weathertrending, they blog about their passion for weather, and how it affects the way we live, every day. Working with household names in the retail and leisure sectors, they create and tailor bespoke weather content for a range of audiences.

Read John’s latest thoughts on the weather for the next few weeks on weathertrending.com

 

Main image: The near dry River Kennet at West Overton near Marlborough on July 10, 2018 in Wiltshire, England. Hot temperatures across the UK for the past few weeks, combined with increased water usage and a short supply of rain during the recent heatwave, has caused very low water levels in many rivers/Credit: Getty

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