North Atlantic Oscillation may causes extreme weather in Europe

A weather phenomenon known as the North Atlantic Oscillation is one possible reason that Europe is presently in a deep freeze.

High atmospheric pressure over Iceland combined with cold air streams from Siberia may be responsible for the freezing temperatures blanketing northern Europe.

Climate scientist Ketil Isaksen says many people are asking the Norwegian Meteorological Institute why -- in a time of concern about global warming -- many countries are experiencing their coldest winter in years.

A handout image obtained on January 8 from NASA, shows a satellite image of the United Kingdom covered in snow. (AFP/NASA/File)

Ketil Isaksen, Climate Scientist, Norwegian Meteorological Institute, said, "This situation is not unusual for Europe and still in a warmer climate we can expect very cold winters from time to time. But the mean temperatures over longer periods, for instance if you look at the time period of 20 or 30 years we see that winter temperatures are increasing. Also, still within this, we have still some cold winters, but they are not so common than before."

Northern Norway is usually the coldest part of the country in winter. However, over the past month southern Norway experienced temperatures down to minus 45 degrees Celsius, while the North had mild temperatures and gale force winds on Sunday.

It's feared the sudden mild weather combined with a heavy downpour in the north could lead to treacherous driving conditions and avalanches.