Weather Eye

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BY PAUL SIMONS

GHOSTLY silver-blue clouds have been appearing in the twilight sky over many parts of Britain this past fortnight or so.

These are noctilucent, or night-shining clouds, and are the highest clouds in the sky, lying about 80km (50 miles) high in the cold, dry air of the mesosphere where temperatures can plunge to –130C (-200F).

The clouds were reported first in 1885, two years after the eruption of Krakatoa, when dust from the volcano set off sensational sunsets around the world. Since then sightings have increased, especially since the 1960s. And whereas they used to be seen largely over the poles, now increasing numbers are being sighted further away, over the UK and beyond, and have brightened considerably over the past 20 years.

This sharply increased activity has led to nagging suspicions that climate change is to blame. As the atmosphere near the Earth’s surface has grown warmer, the mesosphere has turned colder, and intensely cold temperatures are needed to form noctilucent clouds. Also, methane may help to form these clouds, and levels of methane pollution have been rising from farming, rubbish tips, vehicles and much else. Methane is a highly potent greenhouse gas, so it is helping to raise world temperatures.

In fact, the exquisite sight of noctilucent clouds over the night skies of Britain may be giving us a very visible warning sign of global warming in action.

Link to Weather Eye source

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BY PAUL SIMONS

IF YOU suffer from astraphobia, fear of lightning, then the Hebrides are probably the best place to be in Britain in the summer — you stand a greater chance of winning the lottery than being hit by lightning there. The islands average only about 0.001 lightning strikes per square kilometre, the lowest summer lightning activity in Britain. This is because the islands rarely get warm enough to kick off cumulonimbus clouds, and they are usually too remote to import thunderstorms from the mainland.

The worst region for lightning in the summer is East Anglia, where the hot ground stokes up thunderstorms or imports them from Europe over the Channel. The lightning capital of Britain is just outside Thetford, Norfolk, scoring an impressive 1,903 strikes on average each summer.

In winter the pattern of thunderstorms is almost a mirror image of the summer, although less frequent. The greatest activity is in western Scotland and northwest Ireland, where warm, unstable air sweeping off the Atlantic can be lifted up over the ground and trigger thunderstorms. The warm sea of the Channel also sets off storms along the South Coast.

Across the whole year, thunderstorm numbers are greatest in the East and South East and least in the North and North West. Thunder occurs in London and Birmingham about 15 days a year, whereas Glasgow averages about 8 days.

Link to Weather Eye source

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BY PAUL SIMONS

SOUTHEAST England was dry every month from November to early September, rivers ran almost dry and the summer turned extremely hot.

That may sound like a long-range forecast for this year, but it was a description of the weather leading up to the Great Fire of London in 1666 — a reminder that droughts and heatwaves in Britain are nothing new.

Samuel Pepys noted a drought as early as March 18, 1666: “So walked to Westminster, very fine fair dry weather, but all cry out for lack of rain.” The summer grew increasingly hot and even several thunderstorms seemed to have little effect on cooling temperatures. “It proved the hottest night that ever I was in in my life, and thundered and lightened all night long and rained hard,” wrote Pepys on July 7.

Even Scotland was baked dry that summer, while in Oxford the rivers ran almost dry, “to the great impoverishment of boatmen”. John Evelyn recorded in his diary how the drought helped to lead to the final calamity: “This season, after so long and extraordinarie a drowth in August and September, as if preparatory for the dreadfull fire.”

The drought left London’s timber buildings tinder dry, and when fire broke out in Pudding Lane on September 2, it was whipped up on hot, dry easterly winds, eventually burning down about 13,200 houses; about four fifths of the city.

Link to Weather Eye source

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BY PAUL SIMONS

THE Loch Ness Discovery Centre, which opened in Edinburgh in April, helps to explain sightings of the world’s most famous monster, and among the various theories of floating logs and prehistoric animals, there are also some interesting weather possibilities.

The waters of the loch are so deep that they settle out into a warm layer near the surface and a colder layer deep below. Winds blowing over the loch can churn up the warmer layer so vigorously that they set off huge underwater waves up to about 40m (130ft) tall in the cold layer. These waves, in turn, can set off strange movements across the loch’s surface that might be mistaken for a large creature moving around, and perhaps even give misleading sonar readings in the waters below.

Another intriguing possibility is a type of whirlwind known as a water devil, a small column of air that whirls off warm waters on a hot day. From a distance a water devil can look uncannily like a monster’s neck and head poking up from the water and can buzz around topsy-turvy, darting in one direction then pausing before whizzing off in another. For added monster appeal, it can create a great commotion of water spray and even monster-like roaring or gurgling noises.

Of course, none of these theories rules out there being a real Loch Ness monster.

Link to Weather Eye source

[Shiny_Bottom_1]

I always find it amazing, that for every phenomina, there usually a logical explanation :unsure:

Quite an interesting article.

[shuggee]

I like the last sentence... So that's all bases covered!

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BY PAUL SIMONS

AFRICA may be about to enjoy a deluge of investment but that will not break the long drought that has afflicted much of the continent this year Millions are at risk from famine in the countries bordering the Sahara such as Mali, Mauritania and Chad, where drought has come on the heels of the plague of locusts last year. The rainy season stopped early in Niger, devastating crops and leading to the biggest shortfall in grain the country has faced for more than 20 years. At least three million people expected to suffer severe hunger over the next few months.

Drought is affecting areas of Ethiopia; parts of Kenya are struggling with a five-year drought that threatens to wipe out the grazing lands for most of the nation’s livestock. Crop failure from drought extends across swaths of Zambia, Zimbabwe, Malawi and Mozambique, leaving more than eight million people hungry.

Vast areas of Africa are now experiencing changing patterns of rainfall as the weather over the past 25 years has become more unpredictable and more extreme. Rainy seasons are coming at the wrong times, with insufficient rains or in such punishing downpours that they set off floods.

Climate change could be to blame for these extremes, and the future is expected to get only worse. In a continent where most farming relies on rainwater, the effects of global warming are disastrous.

Link to Weather Eye source

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BY PAUL SIMONS

PRESIDENT HU of China is one of the leaders at the G8 summit in Scotland who does not need reminding of the problems caused by global warming and greenhouse gas pollution.

For the past 50 years choking sandstorms have enveloped Beijing each spring. The sand blows in from Mongolia’s expanding deserts, and the nearest sand dune is now less than 100 miles from Beijing. About 10,400sq km (4,000sq miles) of land turns to sand each year, and nearly a fifth of mainland China is now desert.

Man-made factors, such as overgrazing by animals, are involved, but northern China’s climate is also growing drier and warmer.

As it warms, the glaciers in the mountains of western China are melting. Almost all are expected to disappear by the end of the century, leaving rivers dry for much of the year and millions of people without a water supply.

While the north and west are turning more arid, China has had record floods in the south and east, and in the southeast rapid urbanisation in the past 25 years has added to rising temperatures.

At the same time, China’s contribution to global warming is increasing as its oil consumption booms and it pushes ahead with a huge programme of new coal-fired power stations — which are one of the worst sources of carbon dioxide.

Link to Weather Eye source

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BY PAUL SIMONS

WHAT will the weather be like in the summer of 2012 for the London Olympics?

The Games are going to be held at the height of summer, from July 27 to August 12, but there is no guarantee of fine weather — far from it. This is one of the wettest periods of the year in the capital, averaging 58mm (2.3in) rainfall in July or August, and there is a chance of rain on six days over the Games. In fact, only November is a wetter month.

However, July has been becoming steadily drier over England and Wales over the past 200 years. In the 1990s rainfall in July was 40 per cent less than in the early 1800s, and the rain these days also tends to come in heavier downpours, often from thunderstorms.

But the Olympics will be held at the hottest time of the year when temperatures peak at about 34C (93F).

The warmth in the capital is boosted by the “heat island effect” of London’s urban landscape that raises temperatures in calm conditions by around 7C compared with the surrounding countryside. Winds at the height of summer tend to be gentle, at 15kmh (9mph).

By 2012, however, climate change could mean that our summers will be even hotter — and the Olympic athletes may have to endure a heatwave of 30C (86F) or even higher.

Link to Weather Eye source

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BY PAUL SIMONS

A HUNDRED years ago, strange lights appeared around Barmouth, West Wales.

For several months there were dozens of reports of lights rising from the ground, often hovering in the air. They ranged in shape from spheres to triangles. Three vicars saw a large ball of fire rise from the ground and suddenly burst. Another account described a white and red light dancing around a moving car.

A reporter from the Daily Mail started out a sceptic but then saw a ball of light hovering above the roof of a chapel. “It came from nowhere and sprang into existence instantaneously. It had a steady, yellow brilliance and did not move. It stood out with electric vividness,” he reported.

Not to be outdone, a correspondent from the Daily Mirror reported: “A soft shimmering radiance flooded the road at our feet. As I looked up, the light was even then fading.”

At the time, a divine explanation was sought for the sightings as a local religious revival was under way. More recently, geological faults in the area have been blamed. There was unusual seismic activity at the time, and only two years before a small earthquake had struck near by — so perhaps geological stresses had somehow created the phenomena.

The Barmouth lights disappeared in July 1905 and remain a mystery.

Link to Weather Eye source

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BY PAUL SIMONS

THERE is some excellent and surprising news from the US. For the first time since official records began in 1950, there were no deaths caused by tornados from April to June, the peak season. On average there are 52 deaths from tornados each year.

The powerful thunderstorms that spawn tornados made relatively few appearances over “Tornado Alley”, the main spawning ground of the storms, which stretches across the Great Plains from Texas to South Dakota.

However, unusual numbers of tornados did strike fur- ther north, along the Canadian border, and this is a clue to the reason for the low number of tornados this year.

The jet stream — a ribbon of wind several miles high — is important for helping to stoke up the supercell thunderstorms. In winter the jet stream blows through the south, then slowly migrates northwards in springtime, sweeping over Tornado Alley and setting off the massive storms and their tornados. But this spring the jet stream migrated north towards Canada much faster than normal, hardly lingering over the Great Plains. Indeed, Oklahoma, in the heart of Tornado Alley, had no tornados this May.

However, the hurricane season in the US is now under way, and these storms can also spawn tornados. Last year there were 300 tornados during the tropical storm season, and this year the number and intensity of hurricanes is expected to be just as severe.

Link to Weather Eye source

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BY PAUL SIMONS

THERE used to be something very special about thunderstorms in Alaska.

They were so rare that, on average, only one thunderstorm a year struck Anchorage, the largest city in the state. But for the past decade there has been a 60 per cent rise in the number of thunderstorms, and already this year seven thunderstorms have struck.

The upsurge in thunderstorms also means more lightning, and that is causing big problems — lightning strikes are sparking off record numbers of forest fires. On the Kenai Peninsula, south of Anchorage, there have been 13 fires sparked by lightning this year — that compares with 12 lightning incidents over the past ten years. This summer more than 400,000 hectares (1 million acres) of forest and scrubland fires have been set ablaze along the south-central coast of Alaska, and fire services have been so stretched that firefighters had to be drafted from outside the state to help.

To blame for the rise in thunderstorms is the increasingly warmer waters of the nearby sea and rising air temperatures across much of Alaska. Mean temperatures across the state have risen by almost 3C in summer and 4C in winter since the 1970s, one of the fastest temperature increases in the world. The driving force behind these rises is probably global warming.

Link to Weather Eye source

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BY PAUL SIMONS

WHEN Hurricane Dennis hit the US on Sunday it was far less damaging than had been predicted. Despite winds of about 190kmh (120mph), the centre of the storm was fairly small and fast-moving, limiting its damage, and as Dennis passed inland it weakened rapidly.

But it was a close run thing. The hurricane killed more than 60 people across Haiti, Cuba and Jamaica before racing across the Gulf of Mexico to the US. Early on Sunday, Dennis exploded into a category 4 storm with winds reaching 230kmh (145mph). As it neared the coast of Alabama, though, the storm hit seas that had been churned up by Tropical Storm Cindy only a few days before. That churning dragged cool water to the sea surface, choking off the warm water that Dennis needed for its energy, and so weakened its winds. Also, the hurricane swung away from the city of Mobile at the last minute and hit a relatively unpopulated area.

But this hurricane season is worryingly active. Dennis is the earliest-known category 4 hurricane and only the second major hurricane to strike America in July — the other one happened in 1916. Also, a record-breaking four “named” storms have hit this year and yet another, Tropical Storm Emily, is heading towards the Caribbean — and the peak of the hurricane season is still two months away.

Link to Weather Eye source

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BY PAUL SIMONS

COUNCIL road gritters in Cumbria and Co Durham have been sent out this week to stop roads melting in the hot weather. Bitumen road surfaces melt, rather like hot toffee, sticking to tyres and ruining roads. The gritters have sprayed roads with crushed rock dust to protect the surfaces.

Our increasingly severe heat waves are causing other engineering problems. Trains have to be slowed down as rails buckle — safety standards demand that train speeds must be cut between 36C-40C (97F-104F), depending on the normal speed limits of the track. When the temperature goes over 40C (104F), the speed restrictions are even more severe.

The building industry is concerned that most British houses were not designed for heat waves and many homes turn into ovens as indoor temperatures soar above 25C (77F), when people feel very uncomfortable.

The fear is that more people will turn to air conditioning for a quick fix, leading to soaring power demands during the summer that could exceed those of winter, as happens in Australia.

Air conditioning is inefficient, uses huge amounts of electricity and puts a strain on utilities. If that electricity is generated by fossil fuels, then the increased power demand will cause even more carbon dioxide to be pumped out. Carbon dioxide emissions from air conditioning have quadrupled in Britain over the past 20 years.

Link to Weather Eye source

[Weather-history]

I think Paul Simons is obsessed with global warming IMO

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BY PAUL SIMONS

THE Open Championship at St Andrews, Fife, had a surprise on Tuesday. Blazing sunshine sent temperatures soaring, with nearby Leuchars recording 29C (84F), the hottest place in the UK for the day.

But an even-bigger surprise came around 4pm, when the wind shifted and a thick fog rolled in off the sea, sending the thermometer plunging to 18C (64F) in only 20 minutes.

This time of year is notorious for coastal fogs in Britain. The surface of the sea is relatively cold, and warm air blowing across the sea can be cooled until its moisture condenses into droplets that we see as fog. If the wind is very light, a bank of fog can sit just offshore while beaches bask in sunshine — but a sea breeze will send the fog rolling into the coast.

In eastern Scotland this sort of sea fret which sweeps in from the North Sea is called a “haar”, and it was this that saved Mary, Queen of Scots when she arrived near Edinburgh on August 19, 1561. As her ship sailed in, a group of English ships, commanded by Mary’s half-brother, James Stewart, was lying in wait to seize her. But a haar set in at just the right time: “The fog settled for miles along the shoreline, heavy and impenetrable,” said one account. Mary ’s ship was unseen, and she landed unharmed.

Link to Weather Eye source

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BY PAUL SIMONS

WHEN people think of natural dangers, most often phenomena such as floods, storms and tornados come to mind. But one of the worst natural hazards in Britain is at the seaside: rip currents.

These are strong currents that run out to sea and can easily drag swimmers from shallow water out beyond their depth. They are particularly powerful in large surf, but are found also around river mouths, estuaries and man-made structures such as piers and groynes.

Despite their name, rip currents are nothing to do with tides. They form when wind, wave and beach conditions together help to push up water on to a shore.

When that water flows back out to sea a large volume can get squeezed into narrow passages such as a under a pier or a sandbar. Water can race out at 6ft (1.8m) a second or even faster, dragging sand, seaweed and much else with it.

It is not always easy to spot a rip current. Watch out for debris floating out to sea, a rippled patch of sea or foam on the water surface.

To get out of trouble, those caught in a rip currents need to keep calm and try to swim parallel to the shore to escape its grip. Do not swim into the current towards the shore because it is too exhausting. If it is possible to stand up, try to wade instead of swimming.

Link to Weather Eye source

[Shiny_Bottom_1]

Great story HC, and some sound advice.

Some of the water disasters you here at this time of year are very saddening, especially as they are only having a paddle/swim.

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BY PAUL SIMONS

FIFTY years ago today, the UK’s greatest single day’s rainfall was recorded in Martinstown, Dorset.

An intense thunderstorm stalled over Dorset, and the picture-postcard village of Martinstown was deluged with 279mm (11in) of rain in 15 hours, most of it falling in an intense four-hour burst. This was a deluge of biblical proportions, bearing in mind that the average rainfall in London is 610mm (24in) for the whole year.

Torrential rains also fell over a surrounding area. Water cascaded down the steep slopes of the Ridgeway hills, setting off landslides and gouging massive holes in the ground. Flash floods struck nearby Dorchester, Weymouth and Bridport, smashing cars, and boulders were strewn across roads. Two people died.

But the flooding could have been far worse. The porous chalk rocks in the area helped to absorb vast amounts of rainwater, like a sponge, although in Martinstown this led to a delayed-action flood as the small local river burst its banks the following day, leaving the village marooned.

July 1955 had been sunny and warm, and temperatures the day before the storm had reached 29C (84F) in Dorset. But a depression sat over northern France, and on July 18 a storm crossed the coast, slowed down, stalled and then dumped its rain over one area.

After the deluge the previous fine, sunny weather returned to Dorset.

Link to Weather Eye source

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BY PAUL SIMONS

THE glorious hot sunshine of the past week was delivered by an Azores high. This is an anticyclone or high-pressure system which is often centred over the tiny subtropical islands of the Azores, about 1,300km (800 miles) west of Portugal.

When a finger of the Azores high pushes towards the UK in summer it usually brings light winds and fine, warm weather. As air gently falls from a great height in this anti-cyclone it warms by compression — try putting your finger over the nozzle of a bicycle pump as you pump it and feel how hot it gets. In the Azores high, that warmth helps to dry the air, killing off most clouds and leaving skies largely sunny.

If the anticyclone moves slowly over the UK it often brings us a long spell of hot weather. For the past several days the Azores high also became blocked in position as it diverted the jet stream — a ribbon of wind several miles high that steers depressions across the Atlantic. For Scotland that diversion of the jet stream was not far enough north, and a belt of rain swept through on Sunday.

Sometimes blocked Azores highs bring exceptional heatwaves, such as the long, hot summer of 1976. Then there were 15 consecutive days, between June 23 and July 7, of scorching weather with temperatures hitting 32C (90F) or more somewhere in the UK.

Link to Weather Eye source

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BY PAUL SIMONS

THERE was mayhem at a caravan park at Exelby, near Bedale, North Yorkshire last Wednesday. A whirlwind reared up in a nearby field, sweeping piles of hay into a funnel of swirling air 50ft (15.2m) high. The “mini tornado”, as it was described, charged into the caravan site, tossing umbrellas and other loose objects into the air and sending them crashing into cars and caravans. One man was knocked unconscious when the awning was ripped off his caravan and fell on his head, but he later made a complete recovery.

This was no tornado. Violent storms are needed to create tornados, and the whirlwind in Exelby seemed to be conjured up out of thin air. It was a dust devil: a vortex generated by warm air spinning off hot ground, often in the afternoon when the surface of the earth has been baked under a hot sun.

The Tornado and Storm Research Organisation has reported several other dust devils during the hot weather over the past fortnight. Most caused no more harm than scattering piles of grass or dust around, but occasionally they have been known to leave a trail of damage and even injuries.

In May 2003 a medic with the British Forces in the deserts of Iraq was lifted 30ft into the air by a dust devil before crashing to the ground — suffering several broken bones.

Link to Weather Eye source

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BY PAUL SIMONS

IF HISTORY is a reliable guide, the first Test match in the series between England and Australia which begins today at Lord’s is unlikely to be rained off.

Only seven days of Test match cricket have been washed out over the past 15 years. For truly atrocious weather during an England v Australia Test we have to go back much further. In 1905 it rained at Lord’s for more than a week before the match on June 15-17, when a remarkable run of thunderstorms struck each day. On August 27, 1968, a thunderstorm flooded the Oval so badly that spectators were invited to help in sweeping water from the pitch.

One of the most spectacular bouts of weather was in 1975. On June 2 play between Derbyshire and Lancashire at Buxton was stopped by snow, though a blistering heatwave set in soon afterwards. At the England v Australia match at Lord’s on July 31-August 5, in the same year the temperature exceeded 30C (86F) — the hottest Test match on record. Australia held out for a draw without too much trouble.

The location of a Test plays a big part in its weather, though. Over the past 125 years the record for the most rain belongs to Old Trafford, Manchester, with 29 days lost to the weather. The driest Test match pitch is Edgbaston, Birmingham, with only 3 days lost.

Link to Weather Eye source

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BY PAUL SIMONS

TODAY is the 200th anniversary of a sea battle that set the scene for Nelson’s victory at Trafalgar.

In April 1805 Napoleon sent a Franco-Spanish fleet to the Caribbean to lure Nelson away from the Channel, thus allowing a massive army to invade England. But much of Napoleon’s navy remained blockaded at Brest while the remainder, commanded by Admiral Pierre de Villeneuve, had a frustrating venture to the West Indies and then sailed back to Europe.

When news of the returning fleet reached the British, Admiral Robert Calder broke off his blockade of French ports and intercepted Villeneuve off Cape Finisterre, northwest Spain, on July 22, 1805. Although the Franco-Spanish fleet was larger, the weather was on Calder’s side. As the British bore down on the enemy line, a fog descended, and in the chaos Calder’s force captured two Spanish ships and inflicted hundreds of enemy casualties.

It was a defeat for the French — Villeneuve fled to Spain for reinforcements and Napoleon finally was forced to abandon his plans to invade Britain. However, the Admiralty blamed Calder for not chasing the enemy — he was relieved of his command, court-martialled and never served at sea again.

After Villeneuve’s fleet ran to Cadiz for reinforcements, Nelson blockaded the port. When Villeneuve ventured out again on October 21 he came to a sorry end at the Battle of Trafalgar.

Link to Weather Eye source

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BY PAUL SIMONS

A WARNING for anyone planning a barbecue this weekend. Rain is moving in from the West, and for once it looks as if the southern half of Britain will experience more wet weather than northern areas.

This is welcome news for gardeners, though. July’s rainfall so far is about 60 per cent below normal in the South East, and 50 per cent in the South West, Midlands and Wales. This follows almost eight months’ poor rainfall over much of southern England.

Although this weekend’s showers will help to water lawns and gardens, do not be tempted to turn on the taps recklessly when the weather eventually turns dry again. The rains are too little and too late to boost water supplies in drought-hit regions.

Very little of the rainwater will sink deep enough to recharge the ground-water supplies that much of the South and East rely on. In fact, most of the rainwater will vanish, evaporating from the ground or in even larger volumes from plants. A mature oak tree can lose about 80 gallons (370 litres) of water a day in summer, while an acre of a thirsty crop such as maize loses about 3,300 gallons (15,000 litres) of water each day.

To make a substantial difference to our water supplies this summer we need weeks of rain, and the chances of that appear fairly remote.

Link to Weather Eye source

[PersianPaladin]

We need 'weeks' of rain to make a substantial difference?

That's utter rubbiDoh a dumb swear filter got the better of me

Don't rely on groundwater! Just collect the water in reservoirs and store it in an efficient way. And i reckon that people waste too much water anyway.