Portal de Periódicos da CAPES

When 1987 blew away the UK…

2015; Wiley; Volume: 70; Linguagem: Inglês

10.1002/wea.2538

1477-8696

Richard Allo,

Flood Risk Assessment and Management

Throughout its history, the United Kingdom has experienced some wet and wild weather, ranging from the rare London tornado of 2006 to the 2012 floods which swept through Great Britain and Ireland. It could be said that for many, the most memorable – and disturbingly frightening to hit the country – was The Great Storm of 1987. It was on the night of 15 October that England, France and the Channel Islands were struck by winds up to 58 ms−1, generated by a severe depression moving northeast from the Bay of Biscay. And with 22 fatalities in England and France, ruined residences, torn trees, chapped chimneys, and damage costs reaching £2 billion, civilians battened down the hatches and braced themselves for one of the most powerful storms ever to hit Western Europe. Approximately 5 days prior to the storm striking, weather forecasters predicted that troubled weather was on its way – but in no way whatsoever did they predict the intensity, which was later delivered on the night of 15/16 October! The storm itself developed in the Bay of Biscay, taking the shape of a depression located west of France and north of Spain. Depressions, famously defined as areas of low atmospheric pressure where cold and warm fronts meet, typically start off in the Atlantic Ocean between latitudes of 30° and 40°. From here, quite literally depressing weather is created, forming furious skies and one formidable storm! In the early hours on 15 October, the first wind warnings were announced for sea areas in the English Channel. Four hours later, however, at 1030 utc, warnings of severe gales were delivered, suggesting a storm of great intensity. At lunchtime, it was then observed that the depression had moved northeast towards the UK and, worse, deepened to 964hPa! That evening, various forms of media were warning all civilians of heavy rain and strong winds, although rain was speculated to be the greater culprit. How wrong this was: winds of up to Force 11 were yet to come! Nonetheless, veteran weatherman Michael Fish appeared to have counted all his eggs, stating, Earlier on today, apparently, a woman rang the BBC and said she heard there was a hurricane on the way; well, if you're watching, don't worry, there isn't, but having said that, actually, the weather will become very windy, but most of the strong winds, incidentally, will be down over Spain and across into France (Daily Mail, 2013). Consequently, alerts were issued to the London Fire Brigade, as well as to the Ministry of Defence at 0135 utc on the morning of 16 October, the latter stating that military assistance may be required to contain the oncoming storm. By the time 2300 utc came, winds of Force 10 were assessed (Figure 1). However, this was increased to gusts of Force 11 once the depression had maneuvered over the English Channel in a northeasterly direction! All I can remember was just wind and noise, 48-year-old Jersey resident Jen Smale (who was 21 at the time) explains, My Mum had a Wendy house in the garden which was completely destroyed, carried right up into the air and smashed on the driveway. (J. Smale, pers. comm.) Somewhat surprisingly, the Channel Islands were battered to terrible extents on such a rare occasion! As residents emerged from their houses the following morning they found their gardens trashed, trees uprooted and roofs blown to shreds (Figure 2). On the night before I remember thinking ‘god, it's a bit windy tonight’, 47-year-old Jersey resident Jon Allo reveals, My Dad's garden fence was gone the next morning, and on the way to work there were trees all over the shop! It was like Godzilla had just rampaged through! (J. Allo, pers. comm.) However, it appeared the south coast of Great Britain was in for tremendous damage, too! Approximately 15 million trees were blown over, with nearly a quarter of Kent's trees brought down (Figure 3). As a result, roads and railways were blocked, causing terrible transport issues. Further, the National Grid underwent atrocious damage, meaning several hundred thousand people were left without power for 2 weeks. I was working in Sussex and living with my wife, 52-year-old Gareth John explains, who was in his mid-twenties at the time. I remember it was so windy the carpets were rising up and down from the floor and then suddenly the window blew in when the metal pole from the outside clothesline smashed the glass. There was also a precarious radio tower by our house which would've crushed us if we weren't evacuated! With our neighbours, we spent the night at the nearby police station. Though the next day our cat came back after running off – dry as a bone! (G. John, pers. comm.) Despite such feline faculty, it appears that even to this day victims of the storm still recall those infamous words declared by Michael Fish, who did predict strong winds despite his errors. I remember watching it on telly the night before! Jon Allo explains, However, we were all pretty frustrated the following morning when we saw the state of our gardens. (J. Allo, pers. comm.) Although the Met Office were criticised for their inaccuracies, improvements were to be made following the passing of the storm. By advancing the quality of observations from satellites, ships and aircraft, observational coverage of the atmosphere over the ocean to the south and west of the UK was increased – making predictions more reliable in future storms to come. As emphasised by weather boffins, the storm of 1987 cannot be classified as a hurricane, for it did not develop in the tropics. Also, wind, measured on the Beaufort Scale, must be 33ms–1 or more and last for at least 10min to be classified as Hurricane Force (or Force 12). However, that doesn't mean to say that the storm itself wasn't extraordinary in terms of its impacts! Shortly after the storm, an official forecaster wrote about an interesting effect which had boosted the storm's power. We now know that the strength of the storm was boosted by a phenomenon known as the ‘Sting Jet’, he explained. In this described effect, cold, dry air lowers into storms high in the atmosphere. If snow or rain falling into this jet of air evaporates and cools the air further then greater energy is added to the storm, causing stronger winds. In 1987, no-one knew Sting Jets existed, the forecaster continued, but now they are well understood and included in forecast models. The storm which affected Scotland in December 2011 was boosted by a Sting Jet, explaining the maximum gust speed of 164mph recorded on top of Cairngorm (Daily Mail, 2013). The winds recorded in the 1987 storm are to be considered as a once in 200 year event – so they occur every two centuries! Some would consider it lucky to witness such a rare storm as powerful as this, though -others would not. What do you think? The chances of another storm with the equivalent power occurring in the near future are relatively low (being a 1 in 200 year event). However, climate change is impacting our weather's behaviour, meaning that extreme weather events are becoming more prominent on the planet. So, by increasing science and technology, can we make an influential difference to the devastation caused by these monsters of the atmosphere?