SCIENTISTS have warned we should brace ourselves for more extreme winters as weather conditions become more volatile, scientists have warned.

A study of seasonal records dating to 1899 found that while most seasons have not changed dramatically, winter has become much more unpredictable.

The results suggest the idea of a typical British winter is increasingly becoming a myth, with wide swings from mild but stormy conditions to extremely cold temperatures and snow in another year becoming more common. Last year's winter was the wettest on record for Scotland, with unsettled conditions meaning temperatures were fairly mild and snowfall was largely confined to the mountains.

Researchers from the East Anglia and Sheffield universities and the Met Office found that seven out of the 10 most extreme winter conditions over the last 115 years have been in the last decade.

Professor Phil Jones, from East Anglia University's climatic research unit, said: "This indicates British winters have become increasingly unsettled.

"If this trend continues, we can expect more volatile UK winter weather in decades to come."

Winter conditions are commonly defined using North Atlantic Oscillation (NAO) - a system of barometric pressure variations that indicates the strength of westerly winds approaching the UK.

When westerly winds are strong, Britain experiences mild, wet and often stormy weather - like last winter.

However, weaker or reverse airflow typically brings cold, snowy weather, such as that in 2009-10 and 2010-11.

The variations were particularly noticeable in early winter.

Mr Jones said: "When we look at the month of December, in particular, our data shows that over the last 115 years, three out of five all-time record high North Atlantic Oscillation values and two out of five record lows took place in the last decade."

Professor Edward Hanna, from Sheffield University's Department of Geography, said it was too soon to say whether the increased volatility was linked to global warming.

But the study, published in the International Journal Of Climatology, states it was extremely unlikely that the clustering of extreme conditions had happened by chance.

The trend could be due to random fluctuations in the climate system, but could equally be due to factors including changing pressure and weather systems over the Arctic, especially Greenland, and changes in energy coming from the sun.

Mr Hanna said: "We cannot use these results directly to predict this winter's weather but, according to the long-term NAO trend, we can say the probability of getting extreme winter weather - either mild/stormy or cold/snowy - has signifi- cantly increased in the last few decades."

William Austin, reader in the Department of Geography and Sustainable Development at St Andrews University and Professor Of Marine Geology at the Scottish Association Of Marine Sciences, said the 115-year range of the study was "long enough to say the results are statistically significant".

Not only does the study show implications for Scotland's weather but it also indicates the more extreme winters are affecting our environment, he said.

Mr Austin added: "NAO has a really strong influence in Scotland. It can have some serious knock-on and far-reaching effects. It also affects our fishing and the environment in the sea lochs. Changes to the amount of fresh water coming into the loch can change the overall marine environment."