ARE WE SET FOR A LONG, COLD WINTER?
THE leaves haven’t yet fallen from the trees and the forecasters are already predicting a bleak start to winter.
After one last sunshine bonanza at the end of next week, when the mercury is set to nudge the mid-20Cs, it will be time to batten down the hatches. According to several forecasters, if you thought last year was bad you ain’t seen nothing yet. Snow by the end of October is just one of the gloomy predictions unveiled in the latest batch of attentiongrabbing long-range forecasts.
The weather is now big business, worth an estimated £500million to companies now rivalling the Met Office and playing a key role in the economy. There’s huge pressure to gaze into the future, allowing us all to make plans. In fact, some companies are now producing forecasts for the next nine months, although stressing they can only be a guide. With the British weather notoriously fickle and prone to change over a matter of hours, how on earth can the forecasters look so far ahead?
It’s done by studying a complex mix of factors, including previous conditions at any given time of year. Even now the temperature of the sea surface in the equatorial part of the Pacific Ocean will have an impact on the British winter to come. If it falls lower than normal for several months, the phenomenon is known as La Niña. The most dramatic effects are seen nearby but La Niña can have an impact on weather thousands of miles away. It influences the jet stream, an intense upper air current that helps the creation of the low pressure fronts which sweep across Britain from the Atlantic, normally bringing wet, mild weather.
La Niña, which typically happens only every three to five years, is in force at the moment and is thought by some experts to be a significant factor in predicting cold winters. However it’s not the only one, making the science of long-range forecasting inexact.
It’s also possible to study conditions in the upper atmosphere to try to predict the likelihood of dominant high pressure zones sitting to the north of the UK during the start of the winter. If this happens mild, wet air from the south-west is blocked and there’s more chance of freezing weather and snow. Another factor is the amount of ice in the Arctic and sea temperatures closer to home.
Ian Currie, a Fellow of the Royal Meteorological Society, says: “All the world’s weather systems are connected. What is going on now in the Pacific can have repercussions later all round the world.”
He says forecasters are also looking for patterns, aided by information from weather stations and satellites.
“In the past five years patterns have emerged of very cold conditions in December, earlier than would normally be expected,” adds Mr Currie. “So it’s not surprising to see these forecasts.”
Paul Michaelwaite, of NetWeather, which correctly predicted last year’s harsh winter and believes we are in for more of the same, says: “The technology which allows us to forecast long-range weather is becoming more sophisticated.
“However, because so many different factors influence the British weather the problem is deciding how much weight to give each. The Holy Grail is to be able to predict several months ahead with 90 per cent accuracy.
“Anyone able to do that would seize a huge chunk of the market.”
For now, although several of the main forecasters appear to concur that it’s going to be colder than normal, there’s often disagreement.
That creates a headache for local councils, airports, supermarkets and motoring organisations. Gavin Hill-Smith of the AA, which dealt with a record 28,000 calls on December 20 last year, says: “We are preparing for the worst but hoping for the best. Every degree the temperature falls in winter increases the number of breakdowns. We do monitor long-range forecasts but most of our weather-related planning is done a week in advance.”
After last year’s fi asco when the nation ground to a halt in November and December, a Government committee has called for more reliance on long-range forecasts and has asked for an extra £10million for improvements to the Met Offi ce.
However, don’t expect a longrange forecast from the Met, which was stung by the reaction to its disastrous “barbecue summer” prediction two years ago. Its three-month outlook is no longer issued to the public, although it does go to government. A £33million supercomputer does the number-crunching.
Spokesman Dave Britton, who declined to comment on the prospects for winter, says: “Because we are a small island, sitting on the edge of a large ocean and a large continent the weather is diffi cult to predict. The public told us that long-range forecasts were not useful. They can never be specifi c.”
WHAT THE FORECASTERS SAY:
Paul Michaelwaite, of NetWeather, is forecasting a cold start to winter based on two computer models.
“October and November will both see below average temperatures. In November we expect the average to be at least one degree colder than usual. We are forecasting an early start to winter and a similar pattern to last year. We don’t claim to be 100 per cent accurate but our longrange forecasts two to three months ahead are pretty reliable and for one month ahead we are usually close to the mark.”
JAMES MADDEN, a forecaster at Exacta Weather which uses analysis of solar activity to provide free longrange forecasts, is already warning of a cold snap.
“As we head towards winter I expect to see the fi rst signs of some moderate to heavy snowfalls as early as October or November in certain parts of the UK. I expect December, January and February to experience below-average temperatures, with the heaviest snowfalls occurring within the timeframe of November to January across many parts of the UK.”
PIERS CORBYN, of WeatherAction, uses historical weather patterns and solar observations to produce long-range forecasts, which he claims are the most accurate of all.
“Forecasts of a cold and dry October will fail. It will be generally wet and mild with divisions across the UK and two dangerous storm periods. Predictions of a cold autumn and winter is baseless hype from a gaggle of wannabes.”
WEATHER SERVICES INTERNATIONAL, a US company, was spot on with last year’s freeze and forecaster Dan Leonard says: “It will be up to one degree below average in the UK for October and November, cooling to one to two degrees below average in December.”
THEWEATHEROUTLOOK, another forecaster, also warns that we should prepare early for winter.
“October may bring a spell of drier and warmer weather before a wet and cold November with a wintry sting rounding off the autumn.”
MICHAEL DUKES, forecast manager for Meteogroup, Europe’s largest private weather company, says: “There’s a higher probability of colder and more snowy weather in the next three months than normal.”
MARK VOGAN, a lorry driver from Lennoxtown, Dunbartonshire, is an amateur forecaster who writes a weather blog: “This year will continue the cycle of colder and snowier than normal winters for the UK. 2011-12 may be one of the worst overall UK winters in the past 100 years with the past two a mere curtain raiser. The worst of the weather will hit just after the New Year.”
