You are currently browsing the tag archive for the ‘Temperature’ tag.

It will have escaped the attention of few people that the UK is on the verge of a remarkably cold spell of weather.

Temperatures are going to drop steadily this week by at least one degree per day, until through the weekend and into the start of next week the temperature will be as much as seven degrees below average.

Some places will by then be struggling to rise above freezing while falling 4 to 9 degrees below in some places overnight.

And it is not just the temperature that will make it feel wintry.

There will be showers breaking out, initially over northern Scotland down the eastern side of Britain, and they will turn increasingly to sleet or snow, especially from Thursday onwards. Showers will also develop down the western side of Wales and across southwest England.

There could be several centimetres of snow accumulating over high ground in north and east Scotland from Thursday onwards, perhaps 15 cm or more in the Cairngorms, and showers will start to fall as snow even at low levels in the south of the country towards the weekend. More regions may become susceptible as showers threaten to become widespread but it is impossible to pinpoint precise locations until nearer the time.

While this depth of cold is highly unusual for November it is not without precedent.

In 1919 the cold began even earlier, with significant snowfalls on 19-20th September, especially over Dartmoor in Devon where 5cm accumulated. Even low ground in the north had snow, and this came after a hot first half of the month: on 11th September the temperature rose over 32 degrees Celsius in Northamptonshire.

When November came around the temperature plummeted again as north-easterly winds set in. The severe cold set in around 11th November 1919, and snow soon followed. At Braemar, Aberdeenshire, snow lay to a depth of 42cm, and over 30cm accumulated on Dartmoor.

Most extraordinary, though, was the frigid temperature recorded at Braemar on 14th November, when the mercury plunged to -23.3 degrees Celsius in the early morning as lying snow chilled the air. The maximum temperature that day was 10 degrees below freezing. This would be extraordinary even in the depths of winter.

The bus from Ballater to Braemar

The Ballater-Braemar bus, not needing any grit evidently.

Snow remained on the ground at Braemar and Balmoral until the end of the month, when it became much less cold, and the rest of the winter was unremarkable, with frequent milder south and south-westerly winds.

This serves to illustrate that a cold blow at the beginning of winter does not necessarily serve as a reliable indicator for the rest of the season. One swallow does not make a summer, nor one snowman a winter.

“It is difficult to make predictions, particularly about the future”.

Much as that might sound like one of Yogi Berra‘s aphorisms, it actually tripped, tongue in cheek, from the lips of the Danish physicist Neils Bohr.

“The future ain’t what it used to be” — now that was Yogi Berra.

Both the physicist and the baseball star were right — sort of — when it comes to weather prediction.

For some of the most unforgiving demands for pinpoint prognostications are made on the much-derided weather forecaster; which is puzzling, given the well-documented difficulty in forecasting our atmosphere’s chaos and volatility, small initial errors rapidly becoming amplified as time progresses. Still, meteorology makes a rod for its own back: the more accurate it becomes then the greater becomes the demand for even more predictive finesse.

Forecasts to about three days ahead can be pretty near the mark, in fact, or in more general terms up to a week or even ten days. But this depends on the relative stability and predictability of the conditions at the time. Experienced meteorologists might have a stab, in very broad terms, at the coming month, and there are specialist seasonal forecasting companies that spend a lot of effort toiling at a three-month forecast that can only indicate wetter/drier/colder/hotter than average. This is the best that can be expected given the huge number of global atmospheric, oceanic and even solar variables that they attempt to reconcile but they can make a profitable business in dealing in such seemingly vague terms.

So why, I wonder, are there individuals — with no apparent credentials — who claim to be able to predict astonishingly nuanced forecasts six months or even more in advance on the flimsiest of evidence?

Ice creams

During spring and early summer the public was bombarded by volleys of churnalism, based on self-aggrandizing press releases, that guaranteed an “ICE-CREAM SUMMER”. The hyperbole promised a hotter and longer summer than 1976, and indeed one of the top three hottest summers (if not the hottest summer) on record, with temperatures steadily rising to a stifling climax in the first two weeks of August when the mercury would soar above 38 Celsius and the national maximum temperature record would fall.

Ridiculous. Ridiculous at the time and astoundingly nonsensical now, here in mid-August, when we are reaching for our umbrellas and sweaters.

The calumny was cemented by subsequent alarming and alarmist forecasts of the worst drought for the UK since 1902, and by confirmation even in late July of record-breaking temperatures around the corner. Note that these forecasts did not originate from any of the more reputed independent weather forecasting companies or from the unfairly maligned UK Met Office (notwithstanding their PR department’s inappropriate and gauche “Barbecue Summer” spin last year, which must have had their meteorologists banging their heads against the wall).

No, these “forecasts” came from a vocal one-man-and-his-dog operation that has gained a reputation simply through the regurgitation in various media of the exaggerated claims expressed in its own press releases. This is no basis for a credible and professional forecasting company. The occasional prediction might come to fruition: but even a blind squirrel sometimes finds a nut. If there is no methodology to this madness then the guesswork is worthless.

More than that, forecasts of extreme heat and drought (indeed the most extreme heat and drought in history) are highly irresponsible and selfish, given the decisions made in many spheres  on the back of such advice — which included admonitions to (now presumably disgruntled) holidaymakers to “staycation” in the UK and forego foreign shores.

How do such clearly faulty forecasts and forecasters gain credence and thrive? Firstly, there is in this country a desire to root for the underdog, for the small player against the corporation or the government department. This is fair enough to a degree but in the latter instance there seems currently to be a depth of opprobrium for and mistrust of the Met Office (and by extension professional meteorologists and meteorological science in general) that has left a perceived credibility void which a far less credible entity has sought to fill.

Secondly, there is an unquenchable human need to foresee the future. There always has been: hence chicken entrails, tea-leaves and crystals balls. Charlatans of every kind will always be ready to satiate such irrational demand.  The blame, therefore, can be partly apportioned to the consumer; but the supplier, when taking unscrupulous advantage of this demand,  must shoulder the lion’s share of the burden.

They are not ice cream vendors; they are selling snake-oil. I am not buying it and neither should you.

Theo.


Ice cream van in the rain