Ken's fascination with forecasting continues

Despite the march of technology, there is still no sure fire way of predicting the weather, as Ken Cook tells reporter Alex Metcalfe

FANS of icy blasts look away now. Copley’s Ken Cook has no time for you “coldies”.
The dale’s Met Office man gives me a piece of his mind as he shows me round his arsenal of weather gadgets.
“I don’t know why people are obsessed with cold,” he says.
“A lot of people in Teesdale like snow and ice until it sticks around.”
Mr Cook has tended to his back yard equipment every morning for the best part of 50 years.
A towering wind detector, an army of ground thermometers, two Stevenson screens and a new sunshine detector all update the Met Office what’s going on several times a day.
“A lot of it is automatic so it goes online on the rare occasion I am not here,” he says.
“The jet stream is quite strong over north America because of the big temperature differential but that’s coming up against blocking high pressure at the moment.”
Meteorology is a happy home for jargon and can easily baffle the uninitiated.
Much of the dale’s weather is shaped by the jet stream – a meandering ribbon of air racing west to east around the earth’s upper atmosphere.
The jet has jumped to life in the past week dragging North Atlantic depressions into the British Isles to give us a wet and windy Christmas.
Despite the odd blunder, weather forecasting has come on leaps and bounds in the last two decades as computer modelling grows ever more powerful.
But the dale’s idiosyncrasies mean Mr Cook’s experienced touch proves pivotal time and again in his daily forecasts.
“The south-east/north-west split means anything from the SE goes right up the dale and anything from the North West tends to shoot down,” he says.
“There are many different effects in the dale – the main factors for Teesdale are the North Sea and the Pennine Ridge.
“The top of the dale is probably one of the wettest parts of the country whereas the bottom is one of the driest.”
The former headteacher’s website is a Mecca for all with an eye on the dale’s weather with dozens of links to all sorts of exotic data.
Among the best weather models beyond five days is the ECMWF’s offering (European Centre for Medium-range Weather Forecasts) which can go out beyond ten days.
Mr Cook says: “People in the Met Office used to call it ‘Early Closing Monday, Wednesday, Friday’ – but it's one of the best now.
“In the last 20 years I would think maybe eight days ahead is as accurate as four days was in those days.
“Programmes in the Met Office and the European office have advanced – it’s working 24/7.”
However, the models aren’t infallible.
Every so often their consistency wanes and their outlooks flip-flop – particularly when something unusual happens, as Mr Cook explains.  
“A lot of models are programmed with climate in mind so when you get a winter like 2010 (the coldest December since 1910) it throws everyone off balance,” he says. 
“Arctic warming is throwing the models awry – it is probably undergoing the lowest amount of ice since they started recording it.
“The fact the Arctic is not as cold any more interferes with the temperature differentials in the tropics and it tends to weaken the jet stream and the polar vortex.
“If the polar vortex weakens then the cold air sinks south over the USA and gives them a cold spell.”
If you’re lost, don’t panic.
The polar vortex is a big low pressure system (depression) which sits at both poles.
When it’s strong and deep, the UK tends to get a mild and wet winter; when it weakens and splits it’s game on for ice and snow – or thereabouts.
With a glut of computer forecasting data now publicly available, the release of all this data has given rise to some less-than-qualified amateurs.
Mr Cook has no truck with them.
“Long-range forecasters are just making money – most of them work for the Daily Express,” he says.
“They are based on gut feelings – what they are saying is what they want to happen.
“Someone told me the Express sells another 10,000 copies with a weather headline.
“They put headlines on one week saying it’ll be the coldest winter in a hundred years then later that week they stick in how it’s warmer than Bermuda.
“People lap it up don't they?”
So what does this winter hold? And does Ken have the answers?
Well, he hints there are some indications of a quiet spell into the new year.
But beyond a week is anyone’s guess.
He adds: “Battleground scenarios like you have now are really interesting because you look at the forecasts and you can guarantee there will be a change by the forecasts tonight.
“Even five or six days out it can change several times a day.
“The Met Office updates come down to climate eventually.
“They say the north and west will be wet and windy and the south and east drier – that’s just our climate.
“When you read their long-range forecasts they are always hedging their bets,”