Weather Eye

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From The Times August 13, 2008

Atlantic depressions blow away pollution

Paul Simons Weather Eye

Is there anything good to say about the weather this August? On the face of it, grey skies, relentless rain and driving wind hardly have any redeeming features. But if we look on the bright side, there is a silver lining to the dark clouds.

Serious bouts of air pollution have been largely absent this summer. Anti-cyclones at this time of year may bring hot sunny weather, but they also often hold stagnant air that contains traffic fumes and cooks them into a concoction of toxic gases that stings the eyes and chokes the lungs. But the Atlantic depressions this summer have washed out, blown away and swamped most pollution. The rain also washed down pollen and gave hay-fever sufferers some relief, which might explain a drop in sales of hay-fever remedies. However, this has been balanced by a surge in remedies for coughs, cold and flu.

Britain’s trees have revelled in the second consecutive summer of wet weather after years of drought that crippled their growth, brought on premature leaf fall and so seriously weakened the trees that many succumbed to new diseases.

The days of hosepipe bans and drought restrictions almost feel like nostalgia. But heavy summer rain also recharges underground water supplies, ready for the next severe drought. Umbrellas, rainproofs, tumble dryers, mops and buckets all sell well when it pours with rain, but there are some other beneficiaries. Last year’s wet summer registered soaring sales of ready-made meals, tinned soup and meatballs as Britons found solace in stodgy winter food. And cinemas, nightclubs, bingo halls and gambling websites all reported brisk business.

http://www.timesonline.co.uk/tol/news/weat...icle4517325.ece

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From The Times August 14, 2008

A beautiful but wet record holder

Paul Simons Weather Eye

Britain is a wet country, as this summer has shown so well. But when it comes to downpours, Sty Head in the Lake District is hard to beat. It is, on average, the wettest place in the UK, awash with 430cm (169.5in) of precipitation a year. Inverness is the wettest city with an average 200cm (79in), closely followed by Blaenau Ffestiniog, Gwynedd, 198cm (78in). The Lake District also holds the record for the UK’s wettest year, in 1954, when the splendidly named Sprinkling Tarn collected 653cm (257in) of precipitation.

These statistics emerged only when a national network of rainfall observers was established in 1860 by the weather enthusiast George Symons. He was inspired by a series of droughts in the 1850s, when he realised that no one knew how much rain fell across Britain. He recruited rainfall observers by making appeals in newspapers, and eventually amassed an army of 3,500 vicars, doctors, teachers and other volunteers.

The result was a picture of national rainfall never appreciated before. Britain was divided between the wet west and dry east, and between rainy uplands and drier lowlands. The driest place was the Thames Estuary and the wettest was the Lake District. But there were anomalies such as eastern Kent, which was wetter than the rest of the South East, and the Wirral, which was unusually dry for the North West. April was unexpectedly dry, confounding folklore, and spring and summer tended to be drier than autumn and winter, although the opposite is true now.

A plaque at 62 Camden Square, London NW1, marks Symons’ home, where he kept an unbroken record of rainfall for 42 years.

http://www.timesonline.co.uk/tol/news/weat...icle4525765.ece

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From The Times August 15, 2008

The underbelly of cumulonimbus

Paul Simons Weather Eye

This week’s huge showers produced some odd clouds across parts of the UK. Dozens of pouches were seen hanging down from the underbelly of low, dark clouds, like lots of cows’ udders. They looked, quite frankly, sinister. But these udders were a sign of exhausted thunderstorms, which is why they are known as mammatus clouds, named after the Latin for breast. Mammatus clouds look so menacing that in the movie Twister their appearance in a sky growing dark and sinister was taken as the signal for everyone to rush for cover just moments before a gigantic tornado struck. In fact, the exact opposite is true — mammatus clouds usually signal that a tornado has passed, and that the thunderstorm is exhausted and the worst of any bad weather is over.

What causes these fantastic clouds is something of a mystery, though. Although they often form on the underbelly of cumulonimbus clouds, they can also appear underneath other clouds as well.

In thunderclouds, one idea is that it rains or hails, cold air is dragged down from high inside the cloud. When that cool air falls out of the cloud it collides with warmer air below. The warm air hugs these cold down-draughts and holds them, rather like eggs in eggcups, creating the pouch-shaped clouds. Gliders and hang gliders need to steer clear of mammatus, though, because there is a great deal of turbulence under the clouds, with sharp gradients of temperature, moisture and wind.

Even without mammatus clouds, cold air falling out from the underside of a thundercloud often spells the death sentence for a thunderstorm, as its fuel of warm, moist air rising upwards is cut off.

http://www.timesonline.co.uk/tol/news/weat...icle4533953.ece

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From The Times August 16, 2008

Melting glaciers are bad news for ski runs

Paul Simons Weather Eye

On September 19, 1991, a couple hiking on a high ridge in the Alps discovered a frozen corpse sticking up from a melting glacier. It seemed to be from the 20th century, possibly a soldier from the First World War. But forensic science examination revealed that this was a prehistoric man more than 5,000 years old, and he was dubbed Ötzi the Iceman. His remains and clothes were well preserved because the body had been iced over quickly after death.

The discovery of Ötzi was a momentous event, but it rang alarm bells for climate experts concerned by melting glaciers. Glaciers are in retreat across much of the world, and in the Alps the melt has accelerated over the past 20 or so years. At the current rate, most glaciers in the Alps will disappear by the middle of this century.

As the ice cover melts, the Alps are defrosting, causing rocks held in place by ice and snow to fall in landslides. Melting glaciers are bad news for high-altitude ski runs that depend on them, especially as lower slopes are running out of snow. The glaciers act as freshwater reservoirs storing winter snowfall and releasing it over the summer, when it is needed for drinking, farming, and hydroelectric power stations.

In these desperate times desperate measures have been sought. Last year 6,000 people stripped naked on a glacier in the Swiss Alps to highlight the need for drastic action to save the glaciers. And three years ago, an attempt was made to slow a glacier’s melt by shielding it with a large sheet of insulating plastic. This summer, German researchers are trying another technique to slow the melting of the Rhône Glacier, using a large screen to trap cold air over the ice. But, like King Canute, these brave efforts to stem the flowing waters are probably doomed.

http://www.timesonline.co.uk/tol/news/weat...icle4543666.ece

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From The Times August 18, 2008

When the Sahara was wet and green

Paul Simons Weather Eye

A prehistoric graveyard has been unearthed in the Sahara desert, revealing Stone Age people who lived there when the land was wet and green. The site is in Niger in the Tenere desert, an intensely dry quarter of the Sahara. Millennia ago it was grassland, where big game roamed and fish swam in huge lakes and rivers. Animal bones scattered all over the area were from wildlife common today in the Serengeti in Tanzania, such as elephants, giraffes and warthogs. Stone Age people known as the Kiffian hunted and fished there 10,000 years ago, and their remains reveal big, powerful people who grew up to 1.8m (6ft) tall, and who must have had a good diet to grow so big.

But 8,000 years ago the Kiffian vanished during a dry period. When the monsoons returned the rains were less plentiful and another tribe, the Tenerians, colonised the area. These were much shorter and less muscular people, who seem to have herded cattle. Then 4,500 years ago the Tenerians also disappeared, possibly in only a few decades, marking the end of human settlement in the desert.

The dramatic swing in the Sahara’s climate, from grassland to desert, was due to a change in the Earth’s orbit. As the Earth spins on its axis, it slowly wobbles in a circle like a spinning top. Thousands of years ago, that wobble strengthened the solar energy during the summer in the northern hemisphere and helped to drag monsoon rains further north. As the Earth’s spin gradually tilted back thousands of years later, the monsoons weakened, and the Sahara became drier, until eventually it turned to desert and left the Stone Age tribes in dire trouble.

http://www.timesonline.co.uk/tol/news/weat...icle4552972.ece

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From The Times August 19, 2008

River of wind ruins our summer

Paul Simons Weather Eye

When is this abysmal weather going to end? Every day brings downpours and floods, with Northern Ireland and the Republic of Ireland awash with floodwaters, landslides and mudslides.

Just like last year, the blame for such weather lies with the jet stream. As this river of wind meanders around the globe a few miles up, it drags depressions along down below. Unfortunately, the jet stream has been meandering too close for comfort, dropping its depressions and their cargo of rains on weather fronts that have crawled along, leaving plenty of time for their deluges.

As unpleasant as these rains have been, though, they really have not been that bad over most of Britain. It would take a colossal rainfall over the rest of the month to beat the record-breaking rainfall of August 1912, when 193mm (7.6in) fell over England and Wales, and which left Norfolk marooned in a sea of floodwater. In fact, we may only match the August of 2004, when 156mm (6.1in) rain fell.

Much of Europe last week was also battered by some exceptionally violent storms that left ten people dead. Thunderstorms in northern Italy unleashed lightning, giant hailstones and vicious winds, and two mountaineers froze to death after apparently getting lost in the Italian Alps. Austria and Poland were also badly hit by wind, rain and hail.

In fact, the jet stream has sliced Europe in two. As the western half felt the depressions, Eastern Europe has had a blisteringly hot summer, as a persistent ridge of high pressure has dug in.

http://www.timesonline.co.uk/tol/news/weat...icle4560262.ece

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From The Times August 20, 2008

Downpours threaten a handsome harvest

Paul Simons Weather Eye

Rain is playing havoc with the harvests at the moment as farmers are struggling to bring in crops in the wet conditions.

Wheat and other cereals had been enjoying a magnificent growing season, with plenty of rain and some warm sunshine. But now the downpours of rain are turning the fields to mud and ruining what could have been a handsome harvest, and many combine harvesters have ground to a halt waiting for drier conditions. And those cereals that have been brought in have very wet grain, which needs to be dried in expensive kilns to make them useable. That affects the quality of grain, so instead of wheat going for a good price to make bread it is being sold cheaply as animal feed. But if the grain gets too wet it sprouts in the field and not even cattle will touch it.

The soggy conditions are making it difficult to harvest most other crops such as lettuce, which does not last well if it is dripping wet. And the market for salads is down in the dumps in any case this summer because grey skies and rain do not put people in the mood for buying salad vegetables.

But some crops are having a thoroughly good season. Spinach enjoys the rain and is producing a bumper crop, and the early potatoes were extremely good this year. However, the bulk of the potatoes are still in the ground and need more sunshine to put on weight. If September and October are warm and sunny we can expect a great harvest of the maincrop potatoes.

And the wet summer has had the bonus of cutting out irrigation costs and water restrictions that have dogged farmers over recent years.

http://www.timesonline.co.uk/tol/news/weat...icle4567915.ece

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From Times Online August 21, 2008

Here come the hurricanes

Paul Simons Weather Eye

The hurricane season is well under way, and the storms are coming thick and fast. Over the past week, Tropical Storm Fay swept though the Caribbean, leading to 14 deaths in Haiti and the Dominican Republic, before landing a fair-sized punch on Florida, even though it did not reach hurricane power. And, unusually, the storm grew more powerful over land instead of running out of steam without warm tropical seas to feed on.

In fact, there are quite a few mysteries about hurricanes, and particularly how they form in the first place. Most hurricanes begin life as a cluster of thunderstorms that roll off the West Coast of Africa. These storms can band together and blow across the Atlantic on the trade winds in what is known as a tropical wave. But only about one in ten tropical waves grows into a hurricane. One reason for this is that the atmosphere over the tropical seas is hostile for hurricanes. Dust storms blowing off the Sahara and high-altitude winds, for example, can kill off a storm. But a recent study gives insight into how embryonic storms can protect themselves from threats in the outside world, by using a pouch.

Rather like the way a kangaroo nurtures its young in a pouch, so a tropical wave seems to incubate a storm in its own weather pouch. This is a warm, moist region that protects the embryonic storm and nurtures it through infancy into adolescence, when the winds circulate in a spinning storm. That rotation is a key stage in the storm’s life, and can eventually intensify into a full-blown hurricane. By looking out for these pouches, meteorologists hope to improve hurricane forecasts.

http://www.timesonline.co.uk/tol/news/weat...icle4575766.ece

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From The Times August 22, 2008

It all sounds very strange

Paul Simons Weather Eye

People in Sudbury, Suffolk, have been plagued by a strange humming during the night for the past several weeks. According to a report on BBC News, the noise lasts from 6pm to 5am, and is described as “an electrical hum, like a whirr”, “a high-pitched continuous drone” or even “like a spacecraft . . . an ethereal noise”. The local district council is trying to track down the source of the disturbance, but so far without success.

In the 1970s Bristol suffered a hum that drove several hundred people up the wall, but the source was never traced. Indeed, these sorts of hums, wherever they occur, seem to be impossible to pin down.

However, another type of hum has been pinpointed to the seas between Greenland and south of Iceland. During the autumn and winter, strong storms kick up rough ocean waves that travel in opposite directions. These waves crash together like giant cymbals and set off vibrations that resonate through the sea, 2km (1.2 miles) deep, rather like a huge water-filled organ pipe. It is just the right depth of sea to make vibrations so powerful that they can be detected thousands of kilometres away on the coasts of North America and Europe, although the sound is far below that which human beings can hear. The vibrations were first recorded in the early 20th century as a strange, continuous buzz on seismometers, instruments that measure earthquakes, and give a history of wave interactions and storms over the ocean. And the ocean hums could also be a powerful tool to examine the properties of the Earth’s crust.

http://www.timesonline.co.uk/tol/news/weat...icle4583154.ece

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The Times August 23, 2008

There's something fishy going on

Paul Simons Weather Eye

Tomorrow marks the 90th anniversary of one of the strangest incidents in British weather. The science journal Nature carried a report of it shortly afterwards. “About 3 o’clock on the afternoon of Saturday, August 24 last, the allotment-holders of a small area in Hendon, a southern suburb of Sunderland, were sheltering in their sheds during a heavy thunder shower when they observed that small fish were being rained to the ground.”

The allotment-holders must have been astonished as they watched hundreds of the fish pour down in a 10-minute burst of torrential rain. The fish were about 75mm (3in) long and specimens sent to a marine laboratory were identified as sand eels, Ammodytes marinus. This is a small, eel-like fish that swims in large shoals around sandy seabeds and is common in the North Sea.

A clue to what lay behind this incident is eyewitness descriptions that the fish were frozen hard, even though it was late summer. It seems likely that a waterspout from a thundercloud over the sea swept up the fish and lifted them into the top of the cloud, where they froze in the icy temperatures. After the waterspout died off, the thunderstorm moved inland, until eventually the mass of sand eels was too heavy to remain airborne, and the whole lot crashed down in an intense downpour.

There have been other incidents in Britain of showers of animals, especially frogs or small fish. In some cases the creatures were encased in ice, which backs up the idea that they were thrown high enough in the thunderclouds to freeze like hailstones. Although most animals are killed by freezing, frogs are surprisingly resilient and can later thaw out on the ground, alive and in rude health.

http://www.timesonline.co.uk/tol/news/weat...icle4592716.ece

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From The Times August 25, 2008

August Bank Holiday has a history of bad weather

Paul Simons Weather Eye

It is that time of year when the nation holds it collective breath and prays for sunshine for the August Bank Holiday. But the history of this public holiday does not inspire much confidence.

When the holiday was introduced in 1871 it fell on the first Monday of August, when there was a better chance of decent weather. But a few washouts during the 1950s and 1960s persuaded the politicians to shift the Bank Holiday to the last Monday in August. It was an amazing act of folly. The first late August Bank Holiday in 1965 was thoroughly autumnal, with showers and a distinctly cold nip in the air, and things went downhill from there. Thunderstorms erupted over the holiday in 1966 and the following year many places were shrouded in thick fog that led to heavy holiday traffic jams.

The weather on this Bank Holiday often signals the change from summer to autumn. None was as dramatic as the long, hot drought of 1976, when everyone expected August to end with a glorious Bank Holiday. Instead, the rain crashed down in a deluge that heralded a soaking wet autumn.

To be fair, the whole of August can sometimes be a damp squib, just like this year. August 1986 was especially grim, but no one imagined that the Bank Holiday would be wrecked by the leftovers of a hurricane called Charley. The remains of the storm turbo-charged a normal Atlantic depression, which went on to batter Britain with colossal downpours and set off serious floods in North Wales.

Scotland probably has the right idea, though. It continues to enjoy the original August Bank Holiday, on the first Monday of the month.

http://www.timesonline.co.uk/tol/news/weat...icle4602333.ece

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From The Times August 26, 2008

Shockwave from Krakatoa eruption registered in London

Paul Simons Weather Eye

Today marks the 125th anniversary of the volcanic eruption of Krakatoa in Indonesia. About 36,000 people were killed in the vicinity and the blast was the loudest noise ever reported, with a shockwave that registered in London.

Tiny particles of ash penetrated the stratosphere to heights of 50km (30 miles) or more, turning the Sun blue or green and causing blood-red sunrises and sunsets.

The New York Times reported on November 28, 1883: “Soon after 5 o’clock the western horizon suddenly flamed into a brilliant scarlet, which crimsoned sky and clouds. People in the streets were startled at the unwonted sight and gathered in little groups on all the corners to gaze into the West. Many thought that a great fire was in progress.” Coloured stripes and bands in the sky appeared over Pennsylvania. “The sky that morning was fairly aglow with crimson and golden fires, when suddenly, to their great astonishment, an immense American flag, composed of the national colors, stood out in bold relief high in the heavens, continuing in view for a considerable length of time.”

The spectacular sights inspired Edvard Munch’s surreal sky in The Scream, as he wrote at the time in Norway: “Clouds like blood and tongues of fire hung above the blue-black fjord and the city.”

Lord Tennyson later offered a poetic scientific explanation of the spectacular skies in his St Telemachus (1892):

Had the fierce ashes of some fiery peak

Been hurl’d so high they ranged about the globe?

For day by day, thro’ many a blood-red eve, . . .

The wrathful sunset glared.

http://www.timesonline.co.uk/tol/news/weat...icle4608256.ece

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From The Times August 27, 2008

Sunshine shortage brings on seasonal gloom

Paul Simons Weather Eye

To call this August a washout is putting it mildly. Day after day of pouring rain is making this a month to forget. Farmers are struggling to get their wet harvests in, ice-cream sales are down in the dumps and summer fêtes have ended in tea tents in soggy disarray. After all these woes, surely this August must have broken a record for rainfall in the UK? And yet a look at the archives reveals something quite astonishing — this August will probably be only the wettest August since 2004.

That summer of four years ago started off reasonably bright but steadily went downhill. July was showery but August turned incredibly wet, with a hefty 156mm (6.1in) average rainfall across England and Wales. Torrential downpours caused bouts of flooding across Britain, but the most dramatic was the flashflood at Boscastle, Cornwall, on August 16.

It is unlikely that England and Wales will come close to breaching that rainfall tally of 2004. The next few days look reasonably dry and, dare it be said, even warm and sunny. The exception is the North, and particularly Scotland, where heavy rains and floods are making life a misery. But even with that sorry state of affairs, the rainfall averaged over the whole UK for August does not look like it will be record breaking.

However, there is another feature of this August that sets it apart from 2004 — it is spectacularly gloomy. Sunshine is in such short supply that it would not be surprising if there were premature cases of seasonal affective disorder, which can happen in bleak summer months. This summer really does feel like a reminder of some of the atrocious summers of the past.

http://www.timesonline.co.uk/tol/news/weat...icle4614649.ece

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From The Times August 28, 2008

Land of will-o’-the-wisp

Paul Simons Weather Eye

Derby is the spookiest city in Britain, according to a recent survey of ghosts and poltergeists in cities across the country. But the Peak District of Derbyshire also has more than its fair share of strange phenomena. Mysterious flickering lights have been seen dancing over crags, peatbogs, heather and wooded valleys; tiny, ghostly flames a few inches high are said to dance around like a lantern moving in zigzag lines.

These lights are known as the will-o’-the-wisp or Jack-o’-lantern and are usually seen in bogs, marshy ground and graveyards. The Longendale Valley and Bleaklow in the Peak District both have a long history of the strange lights, and legends say that these were fairies, witches or possibly the ghostly torches of Roman soldiers. Tales also told of travellers led into treacherous bogs, which is why they used to be called ignis fatuus, the foolish light. But in Jane Eyre, a will-o’-the-wisp guides Jane to safety when she is lost on the moor: “Far in among the marshes and the ridges, a light sprang up. This light was my forlorn hope: I must gain it.”

In The Song of Hiawatha Henry Wadsworth Longfellow had an idea of what caused the phenomenon. As Hiawatha made his way through the swamp to slay the magician Megissogwon, the dark waters were: “Rank with flags and leaves of lilies, Stagnant, lifeless, dreary, dismal, Lighted by the shimmering moonlight, And by will-o’-the-wisps illumined, Fires by ghosts of dead men kindled.”

The phenomenon is thought to be caused by gases given off from rotten animal and vegetable matter. These marshy gases such as methane may be ignited by another gas, diphosphane, creating the glowing, flickering light.

http://www.timesonline.co.uk/tol/news/weat...icle4621892.ece

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From The Times August 29, 2008

The not so bracing sea air

Paul Simons Weather Eye

Exactly a century ago John Hassall drew his poster of a jolly fisherman skipping over a sandy beach with the slogan “Skegness is SO Bracing.” It summed up how the Victorians loved the seaside air, as a tonic to breathe in deep for health and wellbeing. But new evidence shows it to be the opposite.

A recent study discovered that dirty smoke from ships is polluting coastal air. Ships burning a cheap sulphur-rich fuel called “bunker oil” produce clouds of tiny sulphate particles. These specks of dirt pose a serious health hazard when breathed in. Air samples taken from the coast of California revealed that sulphates from ships made up almost half the fine particles floating in the air. However, from 2015 United Nations international maritime regulations will make ships burn cleaner fuels when they come near to coastlines.

Another problem floating around at the seaside is entirely natural. The Victorians thought that the bracing air and distinctive smell of the seaside was created by ozone, and that this was wonderful for health. They were wrong on both counts – the smell is not ozone, which is extremely harmful. Instead, University of East Anglia scientists found the smell comes from dimethyl sulphide (DMS), which in high concentrations can irritate the eyes and lungs. DMS released from the oceans affects the weather by helping to seed clouds. With more clouds, less sunlight reaches the sea and so cools off temperatures over oceans. Many scientists believe that DMS is one of Nature’s checks and balances to keep the climate in harmony, and may help to offset global warming

http://www.timesonline.co.uk/tol/news/weat...icle4629489.ece

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From The Times August 30, 2008

Is Manchester's wet reputation just?

Paul Simons Weather Eye

The Serbian and Manchester United footballer Nemanja Vidic caused a storm when he criticised Manchester’s climate, among other things. “You get only a brief glimpse of sunlight before it’s all cloudy again. The winters are mild, but in summer the temperatures seldom go higher than 20C. And it rains, rains, rains.”

Manchester has long been the butt of wet weather jokes, but is it fair? In a survey of Britain’s wettest cities, Manchester came ninth, behind Swansea, Lancaster, Carlisle, Belfast and Glasgow. In fact, the average yearly rainfall for Manchester is only a touch more than for the whole of England.

Manchester’s wet reputation could have something to do with its industrial heritage. Coal smoke from factories helped to seed clouds and create depressing drizzle. But the smoke has largely disappeared and Manchester is far sunnier – the average hours of sunshine have risen 30 per cent in the past 50 years.

Manchester is a victim of geography, though. Moist winds blowing off the Atlantic rise up over the Pennines and drop their rains on the western side of the hills. And because the city is in the northwest, it receives more Atlantic depressions, which tend to veer northwards.

Summers in Manchester also tend to be wet, which puts a dampener on outdoor life. To get some idea of the problem, summer rains in Manchester last 75 per cent longer than in London and a third more than Birmingham. And when it is not raining, it is often cloudy.

As for Vidic, if he finds Manchester’s climate so unbearable he should steer well clear of Glasgow. The rains there are heavier, last longer, and it is colder on average.

http://www.timesonline.co.uk/tol/news/weat...icle4636848.ece

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From The Times September 1, 2008

Is Edinburgh really our most miserable city?

Paul Simons Weather Eye

The least happy place in Britain has been named as Edinburgh (The Times, August 28). In a recent study the city came bottom out of 273 locations across the country. Researchers at Sheffield and Manchester universities based their findings on more than 5,000 responses from the annual British Household Panel Survey, and included climate factors such as hours of sunshine and air pollution.

So, could Edinburgh’s climate make it a miserable place to live in? As Robert Louis Stevenson observed: “She is liable to be beaten upon by all the winds that blow, to be drenched with rain, to be buried in cold sea fogs.”

But Edinburgh has a better climate than is often assumed. Its average yearly rainfall is only 16mm (0.6in) more than London, and less than Birmingham or Plymouth. And it could be argued that the climate of Edinburgh is more pleasant than Glasgow — significantly drier, slightly sunnier and even warmer over parts of the year. It is a famously windy city, but the winds also blow away air pollution.

All told, the climate of Edinburgh is mild. The influence of the Gulf Stream is partly responsible, and occasional warm föhn winds sweep down from the mountains. Those same mountains also ensure that wet westerly winds drop most of their rains over Glasgow, rather than Edinburgh.

But there is one peculiar aspect of Edinburgh’s windy climate. Weather records going back 200 years revealed that its worst bouts of winter storms followed big volcanic eruptions in 1815, 1883 and 1982. Why this happened is not known.

http://www.timesonline.co.uk/tol/news/weat...icle4648813.ece

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From The Times September 2, 2008

Twilights of Europe

Paul Simons Weather Eye

On Saturday much of the country was bathed in sunshine. And in the evening there was a rare chance to see a fantastic twilight long after the sun had set below the horizon. The sky was awash with glorious colours: yellow at the horizon, blending into orange, then red and reaching purple towards the night sky above. Similar twilights were seen across much of Europe.

These skies were created by a volcano off the coast of Alaska. Between August 7 and 8, three huge eruptions rocked the Kasatochi Volcano in the remote Aleutian Islands. A thick plume of ash rose high into the atmosphere, along with about 1.5 million tons of sulphur dioxide, the largest volcanic sulphur cloud produced for 17 years. Airlines diverted or cancelled flights in the region of the volcanic cloud to avoid serious damage to aircraft.

The volcanic cloud gradually swept around the northern hemisphere as a thin veil of dust and acid. That veil scattered the light from the setting Sun to produce fantastic colours, and also produced unusually long-lasting twilight by reflecting the light from the Sun hidden below the horizon.

The curious sunsets of volcanic clouds are so striking that they have had a noticeable impact on works of art through history. Turner’s pictures of vivid red sunsets followed three big eruptions in his lifetime, and his work was no exception. A scientific study of 554 paintings by 181 artists, including Gustav Klimt and Edgar Degas, revealed that 54 of the pictures showed the characteristic colours of volcanic sunsets, and were painted within three years of volcanic eruptions.

http://www.timesonline.co.uk/tol/news/weat...icle4656170.ece

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From The Times September 3, 2008

Launch pad of hurricanes lies in West Africa

Paul Simons Weather Eye

Lousiana may have been spared the widely expected large scale devastation at the hands of Hurricane Gustav, but there is plenty of other trouble in store.

As the residents of New Orleans think about returning to their homes, populations along the coast of Georgia and South Carolina are ready to evacuate theirs. Hurricane Hannah has been churning slowly through the Atlantic for some time, and struck the Bahamas on Tuesday 2 September. It is expected to gather speed and power before launching an assault on the East Coast of the US, possibly on Friday.

Hot on the heels of Hannah will come Tropical Storm Ike, expected to become a hurricane before striking the Bahamas. And behind that is Tropical Depression 10, out in the open Atlantic.

This is now the peak of the hurricane season, and most storms develop along “Hurricane Alley”, which stretches across the tropical Atlantic seas.

West Africa is the launch pad for most of the trouble, starting off as thunderstorms that roll off the coast on to the sea. If these thunderstorms form a cluster they can get blown westwards on the trade winds, and are known as tropical waves. As these clusters sail over the warm seas, they feed off the warm waters, grow stronger and can start to rotate into a tropical depression, which is then given a number. The storms spiral into a familiar shape and gather more strength, turn into tropical storms and are given a name.

Eventually these can develop into hurricanes. However, hurricanes are actually quite unusual — only about one out of ten tropical waves develops into a hurricane.

http://www.timesonline.co.uk/tol/news/weat...icle4662980.ece

[acbrixton]

"But Edinburgh has a better climate than is often assumed. Its average yearly rainfall is only 16mm (0.6in) more than London, and less than Birmingham or Plymouth."

Nonsense. UKMO rainfall data (1971-2000) for Greenwich and Edinburgh are:

Greenwich: annual rainfall= 583.6mm (106.50 days with more than 1mm rain);

Edinburgh: annual rainfall= 676.2mm (120.70 days with more than 1mm rain).

Thus the difference in annual rainfall is more like 3.6" p.a. (that is still a rather smaller difference than I had imagined...).

regards

ACB

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From The Times September 4, 2008

Hurricane Gustav damaged by wind shear

Paul Simons Weather Eye

After the mass evacuation of New Orleans, Hurricane Gustav was not quite the monster storm that was feared, but it was a narrow escape.

On Monday Gustav struck the Gulf Coast as a Category 2 storm with winds of 179km/h (111mph) – weaker than expected, but stronger than the storm of October 1987 in England. So why did Gustav weaken?

When the storm passed over Cuba, it slowed down somewhat and got slightly roughed up. Afterwards the storm swept over a current of warm water, which should have supercharged it into something far stronger. But winds high up above were blowing at different speeds and altitudes, and this wind shear damaged the storm. Gustav did not recover from that assault, and having passed over the warm water current it hit a cooler patch of sea and lost power again.

If the wind shear had not sapped its strength, Gustav would have been a far worse threat: Louisiana and New Orleans had a lucky escape.

But there is no time for complacency. There are currently four tropical storms swirling around the Atlantic. Gustav is now far weaker but creating havoc inland in the US by dropping phenomenal amounts of rain. Tropical Storm Hannah is growing stronger and is forecast to hit the East Coast of the US tomorrow, anywhere from Florida to South Carolina. Tropical Storm Ike is following in its wake and steering towards the Bahamas. Behind that is Tropical Storm Josephine far out in the Atlantic. Such a flurry of Atlantic storms at the same time is quite unusual, and highlights what an active hurricane season this is turning out to be.

http://www.timesonline.co.uk/tol/news/weat...icle4670074.ece

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From The Times September 5, 2008

Record-breaking hailstones in Horsham

Paul Simons Weather Eye

On this day 50 years ago the largest and heaviest hailstone officially recorded in the UK fell at Horsham, Sussex. On a hot and humid day around 6pm the sky turned ink-black. “The storm struck like a bomb . . . within a few minutes the air seemed to become a solid mass of rain, hailstones and crushing wind,” reported the West Sussex County Times. Residents likened it to an air raid, and one woman described being struck on the head. “At first I thought I had been struck by lightning. I was almost knocked out”, while another witness said: “It sounded like a lot of machine gunning, the noise of cracking glass was terrible.”

Hundreds of roofs were smashed, windows shattered and apple trees stripped bare. The record-breaking hailstone weighed 190g (6.7oz) and measured 6.35cm (2.5in) in diameter, heavier and larger than a cricket ball. It was astonishing that only three people were injured and none was seriously hurt.

A tornado also tore through the outskirts of the town, sending chimneys crashing through roofs and uprooting trees. A petrol station was blown apart, with little more than its walls standing, a petrol pump thrown into the middle of the road, and the corrugated roof flung a quarter of a mile away.

The hailstorm cut a swath through Sussex, forcing an aircraft to make an emergency landing at Gatwick after being badly damaged by giant hailstones. Thunderstorms swept the whole of southeast England and brought chaos with widespread flooding that cut road and rail links, while lightning set fire to two fuel storage tanks at an oil refinery in Kent.

http://www.timesonline.co.uk/tol/news/weat...icle4677963.ece

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From The Times September 6, 2008

Grace Darling honoured after assisting rescue

Paul Simons Weather Eye

On September 7, 1838, the steamship Forfarshire bound for Dundee from Hull ran into problems with its boilers. The engine room flooded just as a storm was brewing, and as the Forfarshire rounded the Farne Islands, off the Northumbrian coast, the engines failed and the ship was left drifting in gale-force northerly winds. At around 3am, the steamer ran aground on rocks and broke in two; 42 passengers and crew drowned. But several survivors climbed off the wreck on to a rock, lashed by winds and waves in bitter cold.

Not far away was the Longstone lighthouse, and at daybreak the lighthouse keeper’s 22-year-old daughter, Grace Darling, spotted the wrecked ship and the survivors huddled on the rock. She woke her father, William, and they rowed a boat through the towering waves for a mile to the rock. While Grace kept the boat steady, her father rescued five of the survivors and rowed back to the lighthouse. He then returned with two of the survivors to rescue the remaining four people.

News of the rescue caused a sensation and captured the nation’s admiration. Grace’s bravery and stamina were commemorated in pictures, posters, on china and chocolate boxes. William Wordsworth even wrote a poem, Grace Darling, in her honour:

. . . every hazard faced

And difficulty mastered, with resolve

That no one breathing should be left to perish,

This last remainder of the crew are all

Placed in the little boat, then o’er the deep

Are safely borne, landed upon the beach.

The Darlings were awarded medals and Queen Victoria donated money to them. Grace became an icon for the Royal National Lifeboat Institution, and their Grace Darling museum at Bamburgh features the original boat used in the rescue.

http://www.timesonline.co.uk/tol/news/weat...icle4688600.ece

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From The Times September 8, 2008

The Arctic is melting quickly

Paul Simons Weather Eye

After a miserable summer in Britain, signs of a warming climate are currently in short supply. But thousands of miles away, the Arctic is melting quickly. Ice shelves hanging into the sea off Ellesmere Island, Canada, collapsed this year and almost a quarter of the ice cover floated away in huge slabs, carrying ancient ice up to 4,500 years old. The ice shelves will not reform.

The vast icecap floating over the Arctic Ocean also shrank with alarming speed. This icecap naturally comes and goes with the seasons, though. It freezes in winter, reaches its greatest area in March and shrinks during the summer. But this summer’s melt left Ellesmere Island exposed, and the sea-ice that would normally keep the ice shelves hemmed in melted away. The famed Northwest Passage around Canada also opened up, and the Northeast Passage around Russia nearly did the same. With another 2 to 3 weeks of melting left to go, the icecap may shrink even more than last year’s record-breaking ice melt.

There are fears that the Arctic may have reached a point of no return. The brilliant whiteness of the Arctic ice cap is like a giant cooler that bounces sunlight back into space and cools the Arctic Ocean and the surrounding frozen lands. But once that ice has gone, the sea and land warm up. By 2030 the entire Arctic sea ice is expected to disappear for several weeks at a time during the summer. That may be good news for shipping companies eyeing shortcuts between the Atlantic and Pacific oceans. But it is a potential disaster for the climate of the Arctic, and quite possibly could have knock-on effects for the rest of the world.

http://www.timesonline.co.uk/tol/news/weat...icle4698110.ece

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From The Times September 9, 2008

September has been heavenly for slugs

Paul Simons Weather Eye

September has continued to be as wet and gloomy as last month, but these conditions have been heavenly for slugs. An explosion in slug numbers across the country has resulted in prized vegetable patches being devastated by an onslaught of slugs in what should have been a glorious growing season.

Slugs need to keep their skin moist, but unlike snails they do not have a shell to retreat to when conditions turn dry. Instead, they hide under bits of wood, leaves and down cracks in the soil. But in the recent mild, rainy weather they have been able to slither and slide all over the ground in broad daylight. The heavy rains make it difficult to use slug pellets effectively, although research at Newcastle upon Tyne University shows that garlic oil is a good alternative treatment.

The rains and the resulting slug attacks could not have come at a worse time for arable farmers. New crops such as winter wheat and oilseed rape are being planted now, and are being attacked mercilessly. “Oilseed rape is particularly vulnerable because the slugs love it and, once attacked, it doesn’t recover,” says Dr Richard Meredith, of Bayer CropScience. The most striking of the marauders is the big Arion ater group of slugs that range in colour from orange to black and are up to 10cm (4in) long. “The big slugs especially are extending their comfort zone, which is usually around the edges of fields, and they are now foraging further infield in the wet weather,” Dr Meredith adds. However, the smaller, less visible slugs are the worst villains. Because they are so numerous, they do most damage.

http://www.timesonline.co.uk/tol/news/weat...icle4709786.ece

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From The Times September 10, 2008

Tropical storms feeding our predictable forecasts

Paul Simons Weather Eye

After a brief respite more wind and rain sweep in this evening from the west and rush across much of the country tomorrow. In fact, the forecast is becoming embarrassingly predictable these days, with a regular mantra of wind and rain. But there is a difference with this next bout – it was partly born from the remains of a tropical storm.

Last week, Tropical Storm Hanna swept round the outer fringes of the West Indies and on Thursday dealt a huge blow to Haiti. Floods and mudslides killed hundreds of people, although the full extent of the devastation is not yet known. Hanna then swung north, skirting close to the Bahamas before striking South Carolina on Saturday. The storm roared up the eastern seaboard and unleashed further heavy downpours, plus a few tornados for good measure. Some of the worst winds and rains in the US struck New York, where a month’s worth of rain fell in just a few hours and interrupted Andy Murray’s semi-final tennis match against Rafael Nadal at the US Open tournament.

Hanna then lost its tropical character before crossing into Canada as a severe storm, although still capable of dropping massive rainfalls. The storm then moved out into the Atlantic and was taken off hurricane forecast maps. But even though the remnants of Hanna no longer resembled a tropical cyclone, they turbocharged the atmosphere over the Atlantic with an injection of hot, humid tropical air. That fuel stoked up an Atlantic gale that will hit Britain with wind, rain and a chunk of air that was sucked up from the waters of the West Indies.

http://www.timesonline.co.uk/tol/news/weat...icle4719856.ece

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From The Times September 10, 2008

Tropical storms feeding our predictable forecasts

Paul Simons Weather Eye

After a brief respite more wind and rain sweep in this evening from the west and rush across much of the country tomorrow. In fact, the forecast is becoming embarrassingly predictable these days, with a regular mantra of wind and rain. But there is a difference with this next bout – it was partly born from the remains of a tropical storm.

Last week, Tropical Storm Hanna swept round the outer fringes of the West Indies and on Thursday dealt a huge blow to Haiti. Floods and mudslides killed hundreds of people, although the full extent of the devastation is not yet known. Hanna then swung north, skirting close to the Bahamas before striking South Carolina on Saturday. The storm roared up the eastern seaboard and unleashed further heavy downpours, plus a few tornados for good measure. Some of the worst winds and rains in the US struck New York, where a month’s worth of rain fell in just a few hours and interrupted Andy Murray’s semi-final tennis match against Rafael Nadal at the US Open tournament.

Hanna then lost its tropical character before crossing into Canada as a severe storm, although still capable of dropping massive rainfalls. The storm then moved out into the Atlantic and was taken off hurricane forecast maps. But even though the remnants of Hanna no longer resembled a tropical cyclone, they turbocharged the atmosphere over the Atlantic with an injection of hot, humid tropical air. That fuel stoked up an Atlantic gale that will hit Britain with wind, rain and a chunk of air that was sucked up from the waters of the West Indies.

http://www.timesonline.co.uk/tol/news/weat...icle4719856.ece

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From The Times September 11, 2008

Hurricane Ike amazed forecasters by losing power

Paul Simons Weather Eye

Hurricane Ike is the most powerful hurricane so far this year. On Saturday it destroyed most of the buildings on the Turks & Caicos Islands as a Category 4 hurricane, reaching wind speeds of 225 km/h (140 mph). It then tore through Cuba and dropped more rain on Haiti, already ravaged by floods from Tropical Storm Hanna last Thursday.

But Ike did not behave according to plan. It seemed to be following in the wake of Hanna as it skirted the outer fringes of the West Indies, apparently preparing for an attack on the East Coast of the US. But forecasters watched in amazement when Ike suddenly turned left towards Cuba, missed Florida and headed deep into the Gulf of Mexico — a very unusual track for a hurricane in mid-September.

It is a treacherous path to take. As the storm swept the length of Cuba it had weakened considerably, but it is now reinvigorating itself in the Gulf’s warm waters, a rich fuel supply that is feeding the storm’s voracious appetite for energy. It was thought that New Orleans would again be in the line of fire, so soon after the mass evacuation for Hurricane Gustav. But Ike now seems to be heading for a strike on Texas, where a million people are preparing to evacuate their homes.

So what made Hurricane Ike take such an unusual track? It was pushed off course by a huge block of high pressure over the southeast corner of the US. Rather like the way a boulder in a river makes water flow around it, so a hurricane is steered around a high-pressure system. Despite their awesome power and size, hurricanes are simply no match for a hefty anti-cyclone.

http://www.timesonline.co.uk/tol/news/weat...icle4726734.ece

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From The Times September 12, 2008

Cosmic force hits Earth

Paul Simons Weather Eye

On March 19 the Earth was hit by a cosmic force capable of blasting the atmosphere and wiping out most life in the world.

This was a gamma ray burst, the most brilliant light event in the universe after the big bang, when the Universe first began. Fortunately for us the recent gamma ray burst came from 7.5 billion light years away, halfway across the known Universe, and too far to cause any damage on Earth. But a team of scientists recently announced that the event was bright enough to see with the naked eye, although it only lasted 40 seconds.

A gamma ray burst comes from the death throes of a giant star that explodes and collapses into a black hole. A jet of gas shoots out and a narrow beam of gamma rays rips through space at close to the speed of light. In fact, the beam is so narrow it is extremely rare to take a direct hit from one.

If a gamma ray burst occurred within our own Milky Way galaxy, a few thousand light years away instead of billions of light years, it is thought capable of destroying a large part of the ozone layer in the Earth’s atmosphere. The climate of the Earth could be wrecked for years afterwards and could set off a mass extinction of life across the world.

Gamma rays are produced by events that generate enormous amounts of energy, such as star explosions or nuclear bomb explosions. In fact, gamma ray bursts were discovered by accident in the late 1960s when US military satellites were used for detecting the telltale gamma rays given off from nuclear bomb tests, but they also caught gamma rays coming from outer space.

http://www.timesonline.co.uk/tol/news/weat...icle4734518.ece

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From The Times September 13, 2008

The wettest summer for over 50 years

Paul Simons Weather Eye

If you thought the weather was bad this summer and autumn, things were even worse 40 years ago. The summer of 1968 was the wettest for more than 50 years, but the worse was to come. For three days from September 14, thunderstorms and a slow-moving depression crawled and then stalled over southeast England. Heavy downpours turned small streams into wild torrents. Reigate, Surrey, received nearly 150mm (6in) of rain, twice the average rainfall for September. At nearby Leigh, a car was washed away when a bridge collapsed. The Army used amphibious vehicles to rescue 150 passengers stranded on a train at Edenbridge, Kent, where an RAF helicopter also mounted a rescue operation to lift people off rooftops. Coastguards used a rocket line to rescue five people stranded on top of their cars at New Bridge, Sussex. Surrey was hit particularly badly, and the River Mole swelled to half a mile wide, causing East Molesey to resemble Venice.

“Southeast England looks like a great lake dotted with islands,” The Times reported. The region from the Hampshire-Sussex border to Essex was paralysed. Water burst into tens of thousands of homes, cars were thrown off roads, and rowing boats were the only feasible transport for many places. Farmers faced ruined crops and drowned sheep. It was one of the most devastating rainfalls to hit southeast England during the 20th century. Although the Thames did not flood, it was a close-run thing. Had the heavy rains fallen farther upriver, the floodwaters could have combined with high tides and potentially inundated London.

The Met Office was heavily criticised for not giving sufficient warning of such a savage storm. The blame was put on inadequate computer power to forecast where and when the rain would fall.

http://www.timesonline.co.uk/tol/news/weat...icle4744741.ece

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From The Times September 15, 2008

Galveston prepared for Hurricane Ike

Paul Simons Weather Eye

Hurricane Ike struck the coast of Texas on Saturday and battered the island of Galveston with a 3.7m (12ft) storm surge. But far worse has hit this region before.

In 1900 Galveston was one of the wealthiest cities in the US and the nation’s biggest cotton port. Despite its vulnerable position on the Gulf of Mexico coast, the local weather forecaster Isaac Cline declared that it could never be seriously damaged by a hurricane. “An absurd delusion,” he called it. His opinion helped to sway Galveston’s decision to reject a proposal to build a protective sea wall.

On September 8, 1900, an exceptionally powerful hurricane struck the Texas coast. Barometer readings plunged and telegraph reports came in of violent seas in the Caribbean heading northwards. Galveston was full of tourists and residents, but fewer than half of them heeded the warnings; some sightseers even came from the mainland to watch the sea crash in.

The hurricane hit in the evening with winds so powerful they lifted a train full of evacuees off the tracks as it was leaving Galveston. A 4.6m (15ft) storm surge burst through the town, tearing buildings from their foundations. “Massive buildings were crushed like eggshells, great timbers were carried through the air as though they were of no weight, and the winds and the waves swept everything before them,” wrote one eyewitness.

An estimated 6,000 to 10,000 people died, far more than in the San Francisco earthquake six years later. It was the greatest natural disaster in US history. Afterwards Galveston built huge storm surge defence walls, but these were not enough to keep out Hurricane Ike.

http://www.timesonline.co.uk/tol/news/weat...icle4753629.ece