By Mail On Sunday Reporter

A BBC weather forecaster has suggested that the Met Office’s super-computer has a ‘warm bias’ which has stopped it predicting bitterly cold spells like the one we have just endured.

Paul Hudson said the error may have crept into the computer’s climate model as a result of successive years of milder weather. His claim was rejected by the Met Office but other experts said there could be flaws in the system, which was first developed 50 years ago.

In a blog, the BBC Look North presenter writes: ‘Clearly there is the rest of January and February to go, but such has been the intensity of the cold spell...it would take something remarkable for the Met Office’s forecast (of a mild winter) to be right.

‘It is also worth remembering that this comes off the back of the now infamous barbecue summer forecast. ‘Could the model, seemingly with an inability to predict colder seasons, have developed a warm bias, after such a long period of milder than average years?’

The Met Office produces its forecasts by feeding information from sources, including satellites and weather stations, into a ‘climate model’. A set of complex equations then predict weather changes.

Mr Hudson appears to be suggesting that data recorded over the past decade of warmer winters could be unduly influencing the computer’s calculations.

However, the Met Office denies this, saying ‘any small biases’ are automatically corrected before it issues seasonal forecasts.

Modern look: Laura Tobin gives tomorrow’s weather forecast using the 3D map created by Metra, who are the Met Office rivals for the next BBC contract

The rumpus comes as the BBC considers dropping the Met Office forecasts after almost 90 years. The contract runs out in April and the broadcaster has been in talks with the New Zealand forecasters, Metra.

Again, accuracy is the issue, with the Met Office coming under severe criticism over the prediction of a barbeque summer last July. The UK suffered a washout. And its forecast of a mild winter attracted derision as temperatures plunged to as low as -22C in parts of Britain.

A poll commissioned by the Sunday Times this weekend found that 74 per cent of people saying they believed forecasts were inaccurate. However, the Met Office staff are still in line for a bonus, with a muted pot of 1million pounds to share out.

Metra already produces graphics for the BBC including the 3D weather map that brough complaints when it was introduced in 2005. A Metra source is quoted as telling the Sunday Times: ‘The BBC is not very happy with the service it has been getting from the Met Office, it thinks it’s too expensive. We have the ability to provide a bespoke service that will undercut it. ‘Because we already produce graphics we’ve got a foot in the door, so we’re optimistic.’

Read more here.

Icecap Note: Though a bit of a welcome break part of the next week or so as some Atlantic air breaks through into western Europe, eventually the action will shift south and more cold will come from the east with perhaps still more snow end of the month.

See also here some insightful comments on dynamical long range forecasting by Dr. Madhav Khandekar.