Weather Eye

[highcliffe2]

BY PAUL SIMONS

DO NOT adjust your set — if your television is receiving the wrong channels, or your radio making strange noises, then the weather could be to blame.

A large and very powerful high-pressure system is sitting over the UK. The air in anti- cyclones falls slowly and as it descends it warms up — rather like a bicycle pump heating up when the piston is pushed in. Air usually gets colder the higher in the sky you go, but in a temperature inversion, a lid of warm air is now sitting on colder air.

Radio and television signals normally get bounced in the troposphere, the lower atmosphere where our weather takes place. But a temperature inversion creates a false ceiling in the troposphere and bounces TV and radio signals more strongly over much longer distances.

This extra bounce is called tropospheric ducting and can send signals travelling up to 1,200km (800 miles) and sometimes beyond 1,600km. This phenomenon is great for amateur radio hams making long-distance calls, but creates a mess for FM radio or UHF television signals.

Low-level temperature inversions can also play spooky tricks. Radio-operated garage doors have been known to flap up and down for no apparent reason because stray radio signals of the right frequency — even from radio-operated model airplanes — have interfered with them.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

THE UK’s weather seems to have flipped. After weeks of wet and windy weather battering western regions, peace has returned and sunshine broken out, whereas eastern areas have been plagued by gloomy low-level clouds.

The reason lies in a huge system of high pressure anchored firmly to the west of Britain. This anti-cyclone is picking up moist air from the Atlantic and wheeling it around its flank, sweeping blankets of cloud over eastern areas on cold northerly winds. But places such as Ireland and Northern Ireland have been closer to the anti-cyclones’s centre, where the pressure of falling air is strong enough to kill off clouds.

Because the pressure in the anti-cyclone is extremely strong, it is stuck in the Atlantic. But as its central core drifts in towards Britain, the high pressure helps to clear skies.

To find out if your area is going to be sunny, watch where the centre of the high pressure is located on the “general situation” weather map on this page — the closer you are to the anti-cyclone’s core, the sunnier your weather.

The outlook is more of the same calm conditions — as long as the anti-cyclone remains in place it will block out wet and windy Atlantic storms, which are being sent on a huge detour into the Mediterranean.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

“Up, up, up, past the Russell hotel

Up, up, up, to the Heaviside layer”

SO GOES the Andrew Lloyd Webber song Journey to the Heaviside Layer in the musical Cats. The Heaviside layer is part of the upper atmosphere and this week marks the anniversary of its discoverer, Oliver Heaviside, who died 80 years ago on February 3, 1925.

Heaviside was originally a telegrapher, but as he became increasingly deaf he began to investigate electricity and made some profound research on electromagnetism. In 1902 he predicted that there was an electrical layer in the atmosphere which reflected radio waves around the Earth’s curvature. This became known as the Heaviside layer, and its existence was proved in 1923 when radio pulses were beamed upwards and reflected down.

The Heaviside layer is part of the ionosphere, roughly 50km (30 miles) to 600km above the surface of the Earth. It is mainly composed of oxygen and nitrogen. As the Sun’s ultraviolet rays strip electrons from these gases, they ionise into an electrical layer — hence the name ionosphere — which can bounce AM radio signals thousands of miles around the Earth.

The radio reflections are affected by the Sun. During the daytime, the highly charged solar wind presses the Heaviside layer closer to the Earth, limiting the radio wave reflections. But at night reception improves as the solar wind drags the ionosphere further away.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

TODAY is Candlemas Day, which is supposed to predict what the remaining six weeks of winter will bring.

Folklore says: “If Candlemas Day be fair and bright/ Winter will have another flight.” There could be a grain of truth in this. A cold, sunny winter’s day often comes from a high-pressure system, especially one that is anchored over Scandinavia.

The rhyme continues: “But if Candlemas Day bring clouds and rain/ Winter is gone and won’t come again.” Wet, grey skies often sweep off the Gulf Stream, bringing mild westerlies. But the outlook today is largely bright and dry for the UK, so watch out for the return of winter.

However, these tend to be only short-term weather predictions. Candlemas Day is more significant because it marks the exact end of the “solar winter”, the three months with the shortest days. Daylight is now increasing rapidly — we are adding almost three minutes of extra light each day until the spring equinox — and for the next three months, the “solar spring”, the heat from sunshine becomes much stronger.

Today is far better known in the US as Groundhog Day, the day on which groundhogs are said to leave their burrow after hibernation. If the groundhog sees his shadow, he will retreat inside for six more weeks of winter; but if there is no shadow, he stays outside because he knows that spring has arrived early.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

WHAT has happened to this winter? You may recall that back in October there were dire warnings of a bitter winter to come, but apart from a few fleeting cold snaps the big freeze has failed to appear.

In fact, January was incredibly mild, the warmest since 1990 across England and Wales, with very little rain and slightly more sun than expected. Even in Scotland and northwest England — which bore the brunt of gales, rain, snow and the occasional blizzard — temperatures were well above the seasonal norm.

There were some even sharper contrasts. The horrendous Carlisle floods on January 9-11 followed huge rains across the region, while some places in eastern and southern England only had 25 per cent of their normal January rainfall.

The reason for the national split was a powerful run of westerly winds lasting five weeks since December, which launched a barrage of wet depressions crashing into western regions. By the time those winds reached the eastern side of the country they were wrung dry.

Then something spectacular happened on January 21. The wild westerlies vanished suddenly as a large block of high pressure built up in the Atlantic and sent the depressions on a wide detour around the UK.

The days of big winter freezes seem to have gone, thanks largely to strong runs of mild westerlies over the past 20 years or so.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

WEDNESDAY was Groundhog Day in America, when folklore says that if a groundhog sees his shadow there will be six more weeks of winter, whereas no shadow will mean that spring will arrive early.

This year the groundhog’s shadow was clear on a bitterly cold, sunny day in Punxsutawney, Pennsylvania, the home of the forecasting groundhog.

North America has had a cold winter, with record snowfall in Boston and spectacular snows in the western mountains. However, whether this trend will continue is anybody’s guess: the groundhogs’ track record of predictions is dismal. A survey revealed that it made only four correct forecasts in the years 1988-2002.

Other living beings have been suspected of having long-range forecasting powers. In autumn, the woolly bear caterpillar of America sported patches of brown fur, a sign that the winter would be harsh. Whether this mechanism is “correct” every year is not known.

In Gujarat, India, the flowering of the golden shower tree predicts the start of the monsoon some 45 days later, and scientists confirm that it works.

In Britain, if the orange ladybird hibernates in leaf litter on the ground in autumn it signals a hard winter, but if it stays out on exposed tree trunks the winter will be mild. The ladybirds are always correct but we do not know why.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

“I dreamed that, as I wandered by the way,

Bare Winter suddenly was changed to Spring.”

Percy Bysshe Shelley

YOU MAY have noticed that the days now are growing lighter at a cracking pace, with daylight increasing by about three minutes each day, whereas just over a month ago it was struggling to add one minute daily. It seems as if we are rushing headlong into springtime and this amazing acceleration is largely thanks to the tilt of the Earth’s axis.

This tilt gives us the seasons. With the northern hemisphere now tilting towards the Sun the days are growing longer. The tilt also means that the Sun is climbing higher in the sky. From its lowest point at the winter solstice, December 21, the Sun’s altitude barely increased. But from mid-January it grew noticeably higher and will reach its greatest height in March.

This means that the further north you go, the greater the increase in daylight. Throughout February daylight increases for London by 1hr 39min, Manchester by 1hr 47min and Aberdeen by 2hr 6min. The most spectacular increase in daylight is at the North Pole, where 24 hours of night will be broken by the first sunrise on March 18 and two days later it will remain light all day long.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

WARNINGS about the Arctic icecap vanishing as the polar climate grows warmer can sometimes seem far-fetched. But a remarkable meeting last week brought the melting icecap into sharp focus — a delegation of Canadians visited Russia to discuss plans for a new shipping route across the Arctic Ocean as it becomes free of ice.

Churchill is a small port town on the Hudson Bay, frozen in for much of the year. But last year it stayed open from July to November, enough to ship small amounts of grain. Scientists predict that by mid-century the seaway from Churchill to Murmansk, Russia, could be ice-free year round, cutting more than 2,000km (1,240 miles) off the North America to North Europe trade route.

The port authorities in Churchill are planning to increase their shipping volume and have dredged the harbour and improved rail links in preparation for heavier cargos that will be shipped to Russia this year.

But the downside is awesome. The disappearance of the Arctic ice wreaks havoc on the world climate because the Arctic icecap acts like a global refrigerator, without which the world will overheat rapidly.

Changes in weather are happening already. For the past 20 years, the atmospheric pressure over the Arctic Ocean has grown lower, which may be helping to create and steer stronger storms across the Atlantic.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

A COUNTRYSIDE carpeted in nodding sunflower heads, fat cobs of ripening sweetcorn and long rows of vines; it may sound like an idyllic scene from southern Europe, but may become familiar in parts of England in a few decades’ time.

This was one scenario described last week at a government conference on how the country’s changing climate could alter the face of farming.

But there are dangers as well. As eastern and southern regions grow increasingly dry during hot summers, water supplies will become desperately short, especially with farmers competing against the greater demands of growing populations.

Farmers in these areas might be banned from taking water for irrigation from rivers and public supplies, and may have to build their own reservoirs to catch winter rains.

In regions such as East Anglia, many of our thirstiest crops, such as potatoes and salad vegetables, might have to be given up. Instead, these crops may have to be grown solely in the West of the country, where rainfall will be more plentiful.

Livestock farming in the East also may have to shift to the wetter pastures of the West, although intense summer heat in many parts will stress animals, affecting their milk yield, fertility and general welfare.

The changing climate could also bring new pests, such as the Colorado beetle. Currently kept at bay by the cool waters of the English Channel, this voracious pest of potato crops might invade our shores as sea temperatures rise.

Link to Weather Eye source

[Shiny_Bottom_1]

Indeed Highcliffe, that some of the worrys in this article, are in fact already starting to appear in our climate.

Take this winter. I wonder what was the last year where we had so little ppn?

[highcliffe2]

Indeed, it also shows just how fragile our climate is.

If we don't start seeing months with at least average rainfall, the south and east could be in big trouble come summer.

[highcliffe2]

BY PAUL SIMONS

BRITAIN’s weather has influenced many artists, but the Tate Britain exhibition Turner Whistler Monet shows how London’s old smogs spurred a monumental change in art — the rise of Impressionism from traditional classic painting.

In Victorian times climate change meant a permanent haze and thick smogs enveloping British cities. Countless coal fires spewed out smoke and sulphur dioxide and in cold, calm weather the toxic fumes mixed with ordinary fog to create the notorious peasouper smogs. These often castweird yellow, orange and even green lights on to the ground.

J. M . W. Turner was the first great artist to be inspired by these spectacular colours. In Rain, Steam and Speed (1844) he shows the swirling smoke from a railway steam engine blending into the multicoloured clouds of smog filling the sky.

Turner’s psychedelic view of London smog set the scene for James Whistler, who spent nights out on the Thames to paint the spooky silhouettes along the foggy river.

Whistler then introduced Claude Monet to the Savoy Hotel, with its stunning views of the Thames. From there Monet painted many of his famous London smogs, many featuring the ghostly Houses of Parliament. He wrote: “Without the fog London wouldn’t be a beautiful city.” Impressionism was firmly established and the course of art history was changed.

Turner Whistler Monet is at the Tate Britain, London SW1, until May 15.

Link to Weather Eye source

[johnholmes]

nice post Ryan, tks for that

[highcliffe2]

BY PAUL SIMONS

YOU have to feel a tinge of sympathy for the Weather Outlook, the online weather service. Its engaging website (www.theweatheroutlook.com) is something of a rallying point for fans of cold winter weather; it features long-range forecasts and a discussion forum for weather fans on the lookout for freezing weather, as well as other interesting meteorology.

For months the site has been abuzz with predictions of a big freeze on the way but, alas for these fans, it has been a spectacularly mild winter on average.

Our cold weather has tended to come in short, sharp bursts with not much in the way of snow: one big snowstorm in November, a white Christmas, a few flurries in the East at the end of January and a snowstorm over the North this past weekend. But these snows tended to melt away almost as soon as they arrived, and some southern parts of England have not had any snow at all. Even Scotland has had far less snowfall than usual, although Scottish ski slopes are now enjoying very good snow.

Despite the chill this week, there is little sign of a major freeze on the way, although in recent weeks it has been a desperately close-run thing — large parts of Europe have been in the grip of a big freeze from an anti-cyclone centred over Russia, which was followed by a ferocious winter storm this weekend.

Link to Weather Eye source

[Shiny_Bottom_1]

Thanks HighCliffe2.

Now that is a contradiction and a half (in terms of model output).

Do you know who Paul Simmons is, and what his background is?

[highcliffe2]

Do you know who Paul Simmons is, and what his background is?

Nope sorry :lol:

[highcliffe2]

BY PAUL SIMONS

THIS WEEK the funeral was held of Sister Lúcia, 97, the last of three children who claimed to have seen apparitions of the Virgin Mary in Fatima, Portugal, during 1917.

People flocked to the field where the children had seen the visions, and on October 13 a crowd of 70,000 witnessed another spectacle. The sun seemed to move around in swirling veils of silver, blue, yellow and white but without hurting the eyes of the onlookers. “It seemed like a wheel of fire which was going to fall on the people,” one witness said. The crowd wept and prayed, and even non-believers fell to their knees in amazement.

But a weather phenomenon may have been at work, and one clue comes in the months after the eruption of Krakatoa in 1883. Reports worldwide described green or blue-coloured suns or disks of coloured light playing around the sun. Volcanic ash had circled the globe and the tiny dust particles scattered sunlight into surreal colours.

Similar sorts of coloured suns are sometimes seen after desert duststorms, and it possible that the crowds at Fatima witnessed a cloud of dust blown over from the Sahara. Interestingly, one witness spoke of yellow spots falling to the ground.

But why such a phenomenon would occur at just the right time in front of such a large crowd is a theological, rather than meteorological, question.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

A READER has written to ask about a strange incident that he remembers occurring in London on an afternoon in the Fifties: “Without a total eclipse, the house went as dark as night,” he said.

The phenomenon may have happened on January 16, 1955. It was a bitterly cold day and snow was falling thickly, when suddenly at about 1pm darkness struck and day seemed to turn into night.

The daylight may have disappeared because of coal-smoke pollution that had been caught up in a cold front. Smoky air from London was swept up, in cold air, to the Chilterns, where it became trapped beneath a lid of warmer air. But when the wind switched round, the polluted air blew back into the city and created a layer of smog so thick it blotted out daylight. The South Coast was plunged into darkness later that afternoon.

Something similar happened in London on October 24, 1933, when a peasouper smog was trapped under a layer of warm air. London has descended into dark gloom in summer, such as on May 27, 1904, when gas lights and candles were needed even at midday.

But coal smoke is not always to blame for sudden bouts of darkness. On May 19, 1780, the sky from New Jersey to Maine grew dark at about noon, caused by soot blown over from huge forest fires far away in western territories.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

HOW LARGE can snowflakes grow? At midday on January 7, 1887, Mr E. J. Lowe in Chepstow, Monmouthshire, could scarcely believe his eyes when he looked up and saw giant snowflakes measuring some 9cm (3.5in) across fluttering down like pieces of paper. He got a grip on himself, fetched a cold saucer and managed to collect ten flakes, weighing them in at a total of 1.4g (0.05oz).

But the world record for the greatest snowflakes belongs to Fort Keogh, Montana. On January 28, 1887, a thick snowshower fell with snowflakes described as “larger than milk pans” — they measured a mindboggling 38cm (15in) across and almost 20cm (8in) thick, according to a report in Monthly Weather Review that year. A postman witnessed these monster flakes over several square miles but there is no record of how he felt when hit by them.

Snowflakes are created from lots of tiny ice crystals stuck together, and giant snowflakes are probably aggregations of flakes frozen together.

Incidentally, large snowflakes make ideal material for snowmen — as long as the temperature is right. When the air is just about freezing, the snowflakes stick together more easily, and squashing them together turns them into a firm ball of snow. But at colder temperatures the snow is more fluffy and is terrible for making snowmen.

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

WEATHER forecasters owe much to an experiment 70 years ago which helped to save Britain in the Second World War. The story began with meteorology in the First World War, when aircraft were often destroyed by thunderstorms. The Scottish physicist Robert Watson-Watt devised a warning system by tracking the interference that thunderstorms cause to radio signals.

After the war, Watson-Watt continued using radio beams to follow thunderstorms but he also picked up radio waves reflected off aircraft far away. He realised that his device, later called radar (radio detection and ranging), could give warning of enemy aircraft.

On February 26, 1935, he gave a secret demonstration for the Air Ministry, using the BBC radio transmitter at Daventry to locate a bomber flying miles away. Radar was rushed into development, and by 1939 aircraft could be detected 100 miles away. Watson-Watt also invented the air defence network which fed radar data to a control centre to direct fighter aircraft. But for that early-warning system the Battle of Britain in 1940 would have been lost.

But wartime radar also picked up reflections from rain, and eventually it was developed for weather forecasters. Today the UK is covered by a radar network for tracking and measuring rainfall, a vital tool in forecasting rain floods.

Link to Weather Eye source

[johnholmes]

nice post that Ryan, tks

[highcliffe2]

BY PAUL SIMONS

THOSE who were surprised by the huge snowfalls in Kent and Sussex so late in the winter have short memories.

Only last year we had snowstorms in March. The month began bitterly cold before snow and sleet hit southeast England, East Anglia and the Midlands on March 9. The snow returned on March 11 and 12, blanketing large swaths of Wales and England, and cold weather struck again in late March. But the month ended warm, so we may at least hope that that pattern repeats itself this year.

In fact, many of us escaped much worse weather as the forecasts in the past few weeks proved to be wrong. The heavy snow forecast for London on Wednesday did not materialise, and last Thursday’s warnings of snow over much of Britain proved correct only in Northern England.

Predicting snow is a nightmare for forecasters because a difference of just a degree or two in air temperature can make the difference between rain and snow. So, some places could get snow while others only a few miles away get rain — or rain falling in the afternoon can turn to snow in the evening as temperatures drop.

Perhaps the problem is summed up by Banquo’s plea to Macbeth: “If you can look into the seeds of time, and say which grain will grow and which will not, speak then to me.”

Link to Weather Eye source

[highcliffe2]

BY PAUL SIMONS

THE bitter cold this month has brought a crop of problems because of the snow and ice, and could create a new danger for the unsuspecting.

Temperatures are fluctuating so wildly that thick snow lying on roofs can repeatedly freeze and thaw, turning meltwater into huge icicles hanging off gutters and ledges. If these break off they can plunge like spears on to unsuspecting people below and cause severe injuries.

This is a particularly serious problem in Russia and North America, where spring thaws regularly lead to dozens of people being injured or even killed by giant icicles, up to several metres long, falling from high buildings. The problem is so bad that in places, such as Chicago, streets have been closed off while icicles are smashed off tall buildings. This winter signs have been placed on pavements warning of the danger from overhead.

Britain is not immune to the threat of icicles. In the big freeze of February 1991, a woman in Dartford, Kent, received severe head injuries from a falling icicle. And an even worse fate befell the unfortunate son of the parish clerk of Bampton, Devon, in 1776. He was killed by an icicle that detached itself from the local church tower and crashed down on him, a tragedy marked by a strange memorial in the church:

“Bless my eyes

Here he lies

In a sad pickle

Kill’d by an icicle.”

Link to Weather Eye source

[johnholmes]

nice link that Ryan, I liked the poem at the end.

[highcliffe2]

BY PAUL SIMONS

THE BIG freeze gripping much of Europe has created some dreadful conditions over the past fortnight, although skiers are enjoying huge snowfalls.

On Thursday the Netherlands had its coldest March night on record, plunging to -20C (-5F) in places. The country also recorded its heaviest snowfalls for more than 20 years, and iceskaters took to frozen canals.

The region of Switzerland bordering France lived up to its nickname, “Swiss Siberia”, with temperatures falling to -34C (-29F) last Tuesday, close to the record for the area. Even southern Europe has felt the icy winds: Madrid recorded its heaviest snowfall in 15 years, and Rome has had its coldest March for 18 years.

The freeze can be blamed partly on the jet stream, a fast ribbon of wind a few miles miles high where cold polar air battles against warm sub-tropical air. The jet stream has swung south over North Africa, allowing cold Arctic air to flood Europe.

If you are looking for an escape from the cold, then Greenland might be appealing. Parts of the country have been enjoying a remarkable heatwave for the past fortnight, with temperatures soaring to 12C (54F), around 30C above normal, thanks to a massive high-pressure system in the mid-Atlantic feeding subtropical air northwards.

Link to Weather Eye source