Category Archives: Weather

Jean Michel Jarre’s Destination Docklands

jarre adIn the autumn of 1988 Jean Michel Jarre staged Destination Docklands – two concerts of lights, lasers, fireworks and music set amid the derelict Royal Docks of east London.

The concerts nearly didn’t happen though. After what seemed like months struggling against council bureaucracy and satisfying concerns over safety Team Jarre were faced with another nightmare on the day: the Great British weather. A howling force 7 westerly hampered preparations for the first concert on the morning of October 8th – a day which turned out to be the wettest day of 1988. Nearly an inch of rain soaked the grandstands and dock area – but the water was the least of production crews worries…

The floating stage, a giant 30m by 40m ‘battleship’ constructed on top of 16 huge steel barges towed down from the north of England especially for the event, was supposed to move from one end of Royal Victoria Dock to the other. But with 400 tonnes of material on board it was thought safer to leave it locked in its berth – leaving whole sections of the crowd in temporary grandstands wondering where the Frenchman was twiddling his knobs. Not that it mattered.

One of the many illustrations of the event by Mark Fisher

Jarre’s outdoor son et lumieres have always been about the spectacle as a whole with searchlights, lasers and fireworks exploding in time to the music. As with his record-breaking Houston show two years prior giant hand-painted Panni images were projected on to buildings – this time the freshly-painted Spillers Millennium Mills building.

If anything the constant wind and intermittent rain added to drama of the show that took the spectator from the Industrial Revolution through the Swingin’ Sixties up to the 1990s. Jarre was joined on stage by Hank Marvin for London Kid and Rendezvous IV. Mireille Pombo and a choir from Mali also joined Jarre on stage for September, a piece he dedicated to Dulcie September, a South African anti-apartheid political activist, who was assassinated in Paris, France, in March of that year.

The concerts were watched by 200,000 people in the Royal Docks area and thousands more in the surrounding streets and parks.

The Royal Docks have come a long way since the concert. Where the crowd stood is now home to the excellent ExCeL exhibition centre. The fledgling London City airport has grown into a convenient European hub. The small STOL planes bound for Edinburgh and Rotterdam have been joined by BAe 146 jets – even though the airport’s initial promise was to refrain from using jets.

A cable car can now whisk you across the Thames and there are plans to turn the adjacent Royal Albert Dock into a tech hub for China.

There’s some footage of the months of preparation that went into the concert on YouTube. The Making of Destination Docklands sets the scene of the difficulties of putting the show together – and includes some fascinating footage of a wasteland that was the Royal Victoria Dock.

Part One of the Mike Mansfield edit of the concert can be found here http://www.youtube.com/watch?v=Z88QqTskJ4c

Spillers Millennium Mill was repainted 25 years ago especially for the concert. It now provides the backdrop for the London Triathlon across from the ExCeL centre
Spillers Millennium Mill was repainted especially for the concert. It now provides the backdrop for the London Triathlon across from the ExCeL centre
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August 10, 2003: UK’s hottest day ever

The UK’s hottest day was recorded on August 10, 2003, when temperatures across the south-east soared above 38C for the first time.

The weather station at Brogdale, the home of the national fruit collection, near Faversham, Kent
The weather station at Brogdale, the home of the national fruit collection, near Faversham, Kent

A study since then has uncovered that the 38.5C (101.3F) value may be anomalous after it became apparent that the Brogdale value was nearly 2C higher than nearby stations – a fact that would normally rule out such a reading. The actual site also leaves something to be desired with the leylandii hedge being too close to the met enclosure – and possibly helping up the temperature. Scientists are a fussy lot and like things to be done properly – believing that the figure of 38.1C recorded at Kew and Gravesend  on August 10 represents the true record.

But the Met Office refuse to budge and are sticking with Brogdale.

I recorded 38.4C in my own back garden – but because it is not an official site it doesn’t count. Other sites close by also set records that day: 37.9C was reached at Epping while another observer at Woodford Green recorded 36.5C at 2.30pm.

Being the weather anorak I am my memories of that day are still very clear. The birth of my first daughter was imminent and my wife and I were frantically trying to finish the kitchen of our house in Leytonstone. I’d borrowed a van off a mate that day to pick up kitchen units from the Stansted area. The old Renault Master didn’t have air conditioning and a faulty fan made the cabin feel like an oven. As we trundled back down the M11 from our trip to ‘You’re Furnished’ I wound down the window to experience what I can only describe as like being blasted with a hairdryer. Obviously anything above normal body temperature of 37C is going to feel warm  – the opposite of the windchill factor you get in winter. Somehow, through all the heat and pouring with sweat, we managed to unload the van at the other end and completed the kitchen.

screenThe day was the peak of the heatwave with just a couple more 30C days before, much to the relief of my wife, cooler weather arrived. Our daughter was born, over two weeks past her due date, on September 7. A sunny, fresh morning I’ll also never forget.

People often ask if it is possible that the record will be broken. Of course with the right synoptics anything is possible. And official records in the UK, and the world, are just a blip of what has gone before. Diaries of events during the July 1808 heatwave, mentioning accounts of people and livestock dropping dead in fields and birds dropping out of the sky, suggest that somewhere in Lincolnshire possibly saw the temperature exceed 40C.

44
44 UK stations recorded values of 30C and over

A report in today’s Express suggests that a heatwave could be on the way. Unless they are looking at a different set of charts I think the report is probably more to boost their sales – figures show that every time the paper splashes on the weather sales spike 10%.

While we may still see the odd hot day, as we did last Thursday when I recorded the year’s second-highest temperature of 33.6C, I don’t think we are going to see a sustained run of 30C plus temperatures. More *heatspike* than *heatwave*. August is likely to be average overall.

Scott Whitehead
@wanstead_meteo
http://www.wansteadweather.co.uk

London’s worst-ever lightning tragedy

©Scott Whitehead
©Scott Whitehead

One of the worst weather-related tragedies ever to hit the London area happened 75 years ago this month.

What started as a bright and sunny day in Valentines Park, Ilford, turned into disaster at ten minutes to five on Monday, 21 August 1939, when lightning struck a corrugated iron shelter where about 30 people, many of them children, had taken cover from a thunderstorm.

Seven people, including five adults and two children, were killed and 21 injured in the incident near an open air swimming pool where earlier families had been enjoying picnics.

The event was recorded in The Times the following day: “About 5 o’clock there was one final flash, followed by a deafening crash. Everyone in the shelter was thrown to the ground and rescuers who had heard the cries of the injured found them piled in a heap. One of the two women killed had most of her clothing torn off. A man was lying dead on the cross-bar of a cycle. A woman at the back of the shelter was lying unconcious with her arms round two screaming children.”

Looking south-east across the cricket pitches, and the site where the open-air swimming pool used to be, to where the tragedy is believed to have happened
Looking south-east across the cricket pitches, and the site where the open-air swimming pool used to be, to where the tragedy is believed to have happened

A survivor of the tragedy, Mrs H. Treves, of Barkingside, told how she had gone to the park that day with her two daughters, June, three, and Shirley, seven,  for a picnic. She told The Times: “Suddenly the storm broke, and we ran for the shelter. Inside there were about 30 people, and we were all huddled at the back away from the rain. I sat on a bench at the back of the shed with June in my arms and Shirley by my side. Suddenly I was flung from the bench. I must have been stunned for some minutes, because when I came to I found Shirley lying beside me and the ground heaped with people who seemed unconscious. I heard June whimpering, and eventually found her beneath three or four people. One of the men lying across her was dead. I escaped with only burns on my side. June had burns to her foot and Shirley burns on her shoulder and foot.”

One woman told how she had a lucky escape. Mrs A. Galey, of Ilford, said: “I stood in the shelter for about 20 minutes, and then something inside me urged me to leave. I had got about 50 yards when there was a flash and I felt numb. I turned around to go back to the shelter, and then saw all the people huddled on the ground. It looked like a battlefield”

Among the injured were a number of electrical workers who had been repairing a cable which ran through the 150-acre park. Neither the hut, which measured about 20ft by 12ft and had a sloping galvanised iron roof, or the two trees immediately behind it, were damaged.

The disaster was reported in the local paper The Recorder three days later
The disaster was reported in the local paper The Recorder three days later

The local paper, The Recorder, reported the horrific scene that unfolded moments after the strike. It describes other park users frantically trying to help the stricken people in the shelter. One of the first on the scene was Mr A.B. Rowe, an A.R.P warden, from Romford. He said: “I was coming from the pool when a boy ran up and said ‘They have been struck’. I went over and found a heap of people, some terribly injured, in the shelter. During the war I saw some terrible sights, but none more horrible than this. Many were terribly burned and others were twisted into all kinds of positions and unable to move.”

Another helper was Mr H.G.B. Goater, of Eastern Avenue, Ilford. He had also been to the pool and was attracted to the scene by the screaming. “It was like a battlefield. I have seen nothing like it. The dead and injured were in a heap in the shelter.” Mr Goater spent several hours going back and forth to King George hospital with his car, first taking the injured for treatment and then waiting to take home some of those who were allowed to leave.

Among the dead was Dorothy Cribbett, of Capel Road, Forest Gate. She had taken shelter in the hut and was waiting for her 11-year-old daughter, Peggy, to join her when the lightning struck. Her grandson, Ian Braithwaite, 44, whom I managed to track down while researching this piece, takes up the story. “As my mother was making her way from the pool to the shelter lightning struck a bicycle that was leaning against the shelter – leading to the deaths of the people.”

Ian, who now lives in Auckland, New Zealand, commenting on the original article, said: “It makes for very grim reading and was far worse than I remember my mother ever talking about. I know my mother found my grandmother dead in the park and for anyone, let alone an 11-year-old to find someone in the condition that was reported must have been absolutely horrendous.”

He added: “It is one of those stories that you think must be made up, especially as I am drawing on childhood memories from over 20 years ago. Also my own mother died when I was 14 and I have no other known relatives from her side of the family. But I remember her telling me that is what happened.”

He continued: “It seems like it was a pretty miserable time for my mum back then. She was only 11 when her mother was killed and when the war started her father took her to Devon where he came from. In 1943 her grandfather was killed in a bombing raid on Torquay by the Germans. In the same raid a bomb was dropped on a nearby church killing 20 children at a Sunday school service. And we think we have it tough today.”

Ian has been trying to piece together memories of his mother and said: “I am hoping that someone may be able to give me more information surrounding this event or if anyone knew my grandmother or my mother. My grandfather’s name was Ernest Charles Cribbett.”

The synoptic chart from the Air Ministry (forerunner of the Met Office) for Monday, August 21, 1939
The synoptic chart from the Air Ministry (forerunner of the Met Office) for Monday, August 21, 1939

The violent storm, in what up to that point had been a mostly cool and changeable summer, brought flooding to areas around the town and several properties were struck by lightning. Whole chimney stacks were brought crashing to the ground when houses in Selborne Road and Courtland Avenue were hit. Another resident in Woodlands Avenue, Ilford, described the moment before their chimney stack crashed into their living room. “There was a blinding flash and a great crash. We thought the house was going to cave in on us: it seemed as though a bomb had dropped on it.”

The storm also affected the Barkingside area. As the rain fell in torrents a chimney stack on two houses in Tomswood Hill was struck by what an occupant of the house described as a “ball of fire that crashed on to the roof and came zig-zagging though the front room and out of the scullery door”.
Elsewhere in London severe flooding in Ealing is mentioned in The Times. And large hailstones were reported in Surrey.

Rainfall in thunderstorms varies greatly – and this storm was no exception. Met Office rainfall data from the day shows that Loxford Park, the closest rainfall station to Valentines Park about a mile to the south-east, recorded 30mm – almost double that of City of London Cemetery, just over 1.5 miles to the north-west of the storm’s centre, which recorded 15.7mm. In view of the rain and the lightning strikes which happened less than a mile away, across the River Roding, Wanstead had a lucky escape that day.

This selection of newspaper bills, produced by Mike Ashworth, shows a media fixated with build up to the start of WW2 while the Daily Sketch and Daily Mirror focused coverage on the horrifying event in Ilford
This selection of newspaper bills, produced by Mike Ashworth, shows a media fixated with build up to the start of WW2 while the Daily Sketch and Daily Mirror focused coverage on the horrifying event in Ilford

While researching this I found it strange that local memory of the incident is very vague. The oldest generation of my family, a few of whom lived off Ilford Lane, cannot recall the incident though I believe quite a few had already moved out of London as part of the evacuation before the Second World War. Perhaps it is also possible that while this incident by today’s standards is horrific it pales into comparison with what was to come just over a year later with the start of the Blitz in September 1940 – which would result in the loss of thousands of lives in the East End and across the UK.

The disaster in Valentines Park equalled the number of deaths of those under a tree on Wandsworth Common in 1914.

Other deaths caused by lighting in London include two women who were killed while walking in Hyde Park in September, 1999.

According to TORRO, the Tornado and Storm Research Organisation, about 30-60 people are struck by lightning each year in Britain of whom, on average, three may be killed.  You can read further on lightning impacts and safety tips to avoid getting struck here. The Met Office also features a page of lightning advice.

Scott Whitehead
@wanstead_meteo
http://www.wansteadweather.co.uk

I would like to thank Redbridge Central Library for their help in accessing the archives for this piece. And to Mike Ashworth who kindly gave permission to use the superb newspaper bills montage. You can see Mike’s work at his Flickr site. Thanks also to the Met Office.

A few thoughts on August

Often with a change of month comes a change of weather. And weather models this morning suggest this phrase will hold true.

mackerel2Looking back over the last ten years August has been the wettest summer month on five occasions. Given that June rainfall was just 38% of average and July rainfall currently (as I write this on 25th) just 28% of average, it is not surprising that August could potentially be the wettest summer month.

The Atlantic looks like it will have cranked back into action by the first week of August bringing us a period of more unsettled weather – a more mobile westerly flow which means cooler conditions than we experienced during most of July.

The first week looks the most unsettled – no huge rainfall totals though there will be rain or showers around, some of them potentially thundery. Temperatures in the low 20s – though up to 25C on any brighter days.

The second week could start quite thundery with potential for a heavy downpour. After this I would expect the Azores high to ridge northwards settling down the weather to give possibly the best weather of the month during the third week – temperatures still in the low to mid 20s with lots of sunshine around and cool nights.

As the high pressure shifts, bringing a more east or south-easterly flow, days could become briefly very warm at the start of the fourth week. However the high pressure could start to drift north as the wider pattern begins to respond to a very active US hurricane season. Though it is a long way off all that extra energy in the Atlantic will begin to feed through to us at the end of the month, turning things unsettled again in time for the August Bank Holiday. September could be very wet indeed.

So in summary the buzzword for August is average overall with decent sunny summer’s days coupled with the odd rainy or showery day. No return of the heatwave – but also not the washout of the last few summers.

Average max temp: 22.5C (normal)
Average min temp: 12.5C (slightly below normal)
Rainfall: 57mm (normal) – this estimated total could be quite conservative in the event of any potent thunderstorms

Scott Whitehead
@wanstead_meteo
http://www.wansteadweather.co.uk

The storm of July 23, 2013

It was the storm that preceded the hottest day of the year when the temperature briefly touched 34C in Wanstead – that’s higher than the official recognised figure of 33.5C at Heathrow and Northolt.

This image by MeteoX shows the storm right over Wanstead
This image by MeteoX shows the storm right over Wanstead

Earlier people all around town and across the country wilted in the heatwave waiting for news on the royal sprog, many of them ignorant that things were about to go bang. But no matter – it’s days like this they say is good to bury bad news – so the weather, it seems, decided to get in on the act too. The first spots of rain fell on an exhausted crack Sky News commentary team outside Buckingham Palace just before midnight. About the same time reports started coming in of thunder in Canning Town and Poplar – but all went quiet after three flashes. Then 11.58pm reports of rain in Luke Howard’s old haunt – Plaistow. My own ride back from town saw reasonably heavy, if somewhat shortlived, rain in Southwark. Yet by the time I reached Aldgate the ground was dry. Things began to liven up again at 1.30am – distant rumbles of thunder getting closer – further reports of multiple thunder, lightning and heavy rain with hail mixed in at 1.45am. Then, bang, the storm hit Wanstead. I failed to get any footage of the event because of the ambient light washing out every shot. Multiple crashes of loud thunder followed by, at one point, dazzling lightning flashes. You know how close a storm is by counting the seconds between lightning and peal of thunder. At 1.51am I barely counted to one between a dazzling flash and one of the loudest cracks of thunder I’ve heard. Only 6.5mm of rain was recorded, though this fell at a rate of 60mm/hr – the highest rate since I put the meteo live online last November. It doubled the previous highest rate! There followed frequent, distant rumblings of thunder to the east along with copious flashes and occasional bursts of rain. Epping recorded 19mm in two storms at 5am and 6.30am. The thunder and oppressive humidity made sleep difficult. And judging by the number of bleary eyes on the school run this morning I wasn’t alone. The were other storms around London and the UK – a notable one in Brixton precipitated this account on Brixton Buzz. And Steve Brice managed to capture the lightning in Gillingham, Kent. Pershore in Worcestershire recorded over 56mm of rain in 3 hours while lightning damaged rail networks. It was one of the most dazzling displays I can remember – certainly the best since probably 2000 if not before. People often ask me what first got me interested in the weather. Until last night I’d almost forgotten that thunderstorms were one of the main attractions. A night to remember – just like the overnight storms in the Eighties I remember as a lad. Scott Whitehead @wanstead_meteo http://www.wansteadweather.co.uk with thanks to @loveloughton for storm updates The following charts show the cell well. The 2mb pressure drop, the 60mm/hr rainfall rate, the 2C dive in temperature, and the sudden gust of wind Image This pressure drop is also reflected in the temperature fall at the same time: 2C in a matter of minutes. Image temp dropgust

The weather gods are with us

St Swithun's reputation as a weather saint is said to have arisen from the translation of his body from a lowly grave to its golden shrine within Winchester cathedral, having been delayed by incessant rain for 40 days
St Swithun’s reputation as a weather saint is said to have arisen from the translation of his body from a lowly grave to its golden shrine within Winchester cathedral, having been delayed by incessant rain for 40 days
Legend has it that the weather on Monday will be the same for the next 40 days.

St Swithun’s day, if thou dost rain,
For forty days it will remain;
St Swithun’s day, if thou be fair,
For forty days ’twill rain na mair.

St Swithun’s Day is probably among the most well known of weather folklore – but, taken at face value, it is probably the most unreliable.

Since 1961 Wanstead has enjoyed 29 dry St Swithun’s Days (56%). From these the longest dry spell that followed was just 18 days, in 2000. On average, if St Swithun’s is dry, the weather stays fair for five days, with rain arriving on the 20th.

Another interesting observation is that the 40-day period that followed a dry St Swithun’s is on average 13% WETTER than if it rained on July 15th.

So what does this mean for the rest of July and the summer? Looking back at other years that have seen a dry and warm pattern in the run up to St Swithun’s Day we should see a continuation of the dry, warm and sunny conditions, perhaps with a thundery breakdown arriving on the 27th.

Putting superstition and singularities aside current weather models back this up, also suggesting an extended period of dry weather lasting well into July. However, the latest jet stream forecast this evening suggests a period of unsettled weather, ie rain, on… 27th. We shall see.

The latest jet stream forecast on Friday, July 12, suggests that the jet will move south over the UK around the 27th
The latest jet stream forecast on Friday, July 12, suggests that the jet will move south over the UK around the 27th

St Swithun was born around 800AD and died on July 2, 862, at Winchester, Hampshire. According to historians he was fond of building churches in places where there were none. St Swithun, who was bishop of Winchester, was buried in the churchyard of the Old Minster at Winchester, where passers by might tread on his grave and where the rain from the eaves might fall on it.

His reputation as a weather saint is said to have arisen from the translation of his body from this lowly grave to its golden shrine within the cathedral, having been delayed by incessant rain for 40 days.

The basis of the St Swithun’s saying follows the fact that by July 15th summer weather patterns are already well established and tend to persist through the coming weeks.

In meterological terms the position of the frontal zone around the end of June to early July, indicated by the position of the jet stream, determines the general weather patterns (hot, cold, dry, wet) for the rest of the summer. Like a little stream in its bed, the frontal zone tends to ‘dig in’ shortly after the summer solstice.

As the path of our weather systems is controlled by the jet stream, a more southerly location of the frontal zone – as happened last year – is likely to bring unsettled, wet and cool weather. On the other hand, a frontal zone shifted further to the north – as is happening this year – will help the Azores high to build over western Europe, thus bringing dry and pleasant weather to the UK.

Other western European countries also have similar St Swithun’s day sayings – that follow the principle rule. In France they say ‘Quand il pleut a la Saint Gervais Il pleut quarante jours apres’ – If it rains on St. Gervais’ day (July 19th), it will rain for fourty days afterward.
In Germany the Siebenschlaefer or seven sleepers day (July 7th, after the Gregorian calendar) refers to the weather patterns of the following seven weeks.

Heatwave? washout? Or just another changeable British summer?

chicken cloudWith all the talk of heatwaves this week it won’t be long before the media switches from piping on about the UK facing “10 years of miserable summers” to “Is our climate getting warmer?”.

But the simple fact is that the UK’s climate has always varied greatly – some years, as in the last two, the pattern for summer has brought mostly miserable weather. Other years we get a run of warm, dry summers.

A case in point was the heatwave of July 1808. Far removed from images of freezing Georgian winters and miserable summers the July of 205 years ago was among the warmest ever. The monthly mean for July 1808, according to the Central England Temperature series, was 18.4C – the 6th hottest July since the beginning of the series in 1659.

Readings taken by Luke Howard at Plaistow show the build up of heat to the 14th. The series on the right, taken in Wanstead, around 3 miles to the north-east, will be added to by the author as July unfolds
Readings taken by Luke Howard at Plaistow show the build up of heat to the 14th. The series on the right, taken in Wanstead, around 3 miles to the north-east, will be added to by the author as July unfolds
Luke Howard, the ‘father of meteorology’ who at the time lived in Plaistow, referred to the heatwave in his diary on July 13th: “Temperature at 9am 84F. The intense heat of the maximum lasted nearly three hours till about 4pm. At 6pm the temperature was 90F.” Another entry mentions a reading taken nearby. “Another at Plashet, a mile and a half eastward, indicated 96F as the maximum under the shade of a house.”
While Howard’s methods of measuring the temperature ran short of modern standards, his thermometer was hung under a laurel bush, the values still give a valid insight into the heatwave.

Tales of the heatwave, which particularly affected east and north-east England, can be seen in letters sent to local newspapers around the country. Many describe labourers dying from heat exhaustion while working in fields. Farm animals and horses suffered a similar fate. One letter from Hull, published in the Coventry Mercury, said: “At Sigglesthorne, the honey in some beehives melted, ran out upon the ground, and most of the bees drowned in it. At Sutton, a lamb and a dog belonging to the Rev Mr Croft of Rowley, expired in the heat; and several birds dropped down dead, while flying over the streets of this town.”
Of course it is impossible to know about the health of people and animals that died but that birds dropped out the sky suggests extreme heat.

screenWhile temperature records of July 1808 are not unheard of in an English summer one record that remains is the size of the hail – which fell in damaging storms when a thundery breakdown arrived on the 15th.

The main storm missed Wanstead and the surrounding area – though Howard, writing in his Plaistow observatory, knew the weather was on the turn: “Dew on the grass, a fine breeze from ENE. Much lightning in the west this night, a few drops of rain.” Howard would have been referring to all the action about 120-odd miles west where one of the most ferocious storms in recorded history was unfolding.

Much was reported in the local press on the days following the storm which affected an area from Somerset northwards. As well as local records Luke Howard also noted national events in his diary: “After several days of uncommon and oppressive heat the city of Gloucester experienced a storm of thunder and lightning which extended many miles round and exceeded in awful phenomena any one remembered for many years past.”

Trees were “shivered to atoms”, livestock killed by lightning, crops were ruined and countless windows and glasshouses smashed by huge hailstones. A lot of the detail of the storm was compiled by a man named Crocker, then governor of Frome school, Somerset. One account from Batcombe describes a hailstone that measured 13.5 inches in circumference. To give you an idea of the size of a 342mm circumference hailstone I, with the help of my daughters, made one of my own.

It is thought the size of the 1808 hailstone may, along with a storm in 1697, be the national record for hailstone size - being 20mm greater in diameter than those measured in a Horsham, Surrey, storm in 1958
It is thought the size of the 1808 hailstone may, along with a storm in 1697, be the national record for hailstone size – being 20mm greater in diameter than those measured in a Horsham, West Sussex, storm in 1958

Howard’s report continues: “The most tremendous circumstance of this storm was the destructive hail shower which accompanied its progress.”

The Tornado and Storm Research Organisation (TORRO) grades haistorms from H1-H10, where the hail increases in size from 5-10 to over 125mm in diameter. From the historic descriptions the 1808 storm was an H8/9.This exceeds the British record made during the Horsham, West Sussex, storm of September 5, 1958, which produced hailstones up to 80mm in diameter. Hailstones for the 1808 storm were about 109mm in diameter. Since 1650 there have been 119 independent H5 hailstorms in England and Wales.

Since 1900 there has been a halving in the frequency of recorded destructive hailstorms. Scientists are undecided on whether this is a result of climate change or just a variability of the British weather. But any future uptick in destructive hail should be tempered by this historic record.

It is my belief that people’s current expectations for summer were raised to unrealistic levels when we had a run of warm, dry summers a few years ago. The fact is that because of our maritime climate warm, dry summers occur in this country only occasionally. ‘Default’ summer weather is changeable, rather cloudy and, for many in the north, rather cool

So, if any media outlets do start coming out with any stories of “unprecedented heat” or “worst storm in history” bear in mind that it has probably all happened before.

Scott Whitehead
@wanstead_meteo
http://www.wansteadweather.co.uk

Whatever happened to proper summer thunderstorms?

Is anyone else yearning for a good old-fashioned summer thunderstorm? As we move in to what is traditionally the most thunderstorm-prone month – the Met Office average for this area is three days of thunder – you would be forgiven for thinking that we have plenty to look forward to.

Looking north toward Aldersbrook. The Flats can be very exposed during a thunderstorm
Looking north toward Aldersbrook. Wanstead Flats, a 186 hectare open space that is larger than Hyde Park, can be very exposed during a thunderstorm

It was George II who some time during the 1730s apparently characterised the British summer by saying that it was ‘three fine days and a thunderstorm’.

The reality these days, at least in this part of the country, is quite different. Yes, brief fine spells do still break down – but the classic stormy nights I can remember being kept awake by when I was a lad in the Eighties are now a distant memory. A look back through the records shows that our most thundery month happened in June 1982, when thunder was heard on 13 days. On the 2nd a woman was killed after being struck by lightning while walking in a park in Willesden. More storms followed over the next couple of days and there were three more deaths in the UK caused by lightning. One thunderstorm over Loughton flooded 200 houses, some up to the ground-floor ceiling and at least 12 properties were struck by lightning. One observer recorded 79mm of rain, one and a half times the monthly average, in 90 minutes.

Despite a couple of instances of good potential for thunder this past month has been, so far, completely thunder-free, with all the activity passing well to our east. On June 20-21, there were 235,809 lightning strikes in 24hrs over Germany. To put that into perspective the UK, on a typical ‘thunder day’ in summer, receives up to 10,000 ground strikes although the exceptional day of 24 July 1994 produced 85,000 ground strikes.

The meteo is sited on the Aldersbrook Estate and uploads data to the web every 10 minutes, 24 hours a day
The meteo is sited on the Aldersbrook Estate and uploads data to the web every 10 minutes, 24 hours a day

So what is the potential for thunder in July? Looking back at Wanstead and the surrounding area’s local records the average number of days that thunder was recorded works out as 3.5 – though some years thunder occurred considerably more than others. But to get thunderstorms first we need the ingredients. The classic scenario happens at the end of a short heatwave, a cold front advancing from the west undercuts hot and humid air that has been in occupation for two or three days. If there is sufficient moisture in the upper atmosphere, cumulonimbus clouds will bubble upwards to the base of the stratosphere, and thunderstorms will soon follow.

Apart from the first couple of unsettled days at the beginning of July the above scenario looks unlikely to happen at least in the first half of the month. The North Atlantic Oscillation is predicted to stay positive into July – this spells good news for us as it suggests that the Azores high will dominate our weather, bringing lots of fine and dry conditions. With the jet stream and westerlies being kept just north of Scotland, temperatures should be average to slightly above. It is possible that the high could further dominate as the month goes on. But it is also possible that pressure will start to fall after around the middle of the month. Though it is impossible to predict in detail perhaps a date of around 20th would be the most likely for thunder?

It is too soon to say if the recent trend for a paucity of thunderstorms is just a blip. It could just be another typical variation of the British weather and we will shortly see an upturn in summer thunderstorm activity.

Scott Whitehead
@wanstead_meteo
wansteadweather.co.uk