Temperatures to plunge again in Britain

London, Jan 25 (IANS) Winter is all set to make a dramatic comeback in Britain with temperatures expected to plunge in March through mid-April, forecasters said.

US firm Weather Services International (WSI) had earlier forecast the big freeze of 2009-2010 as well as the recent pre-Christmas arctic conditions.

It says that while most of Britain will be mild for much of February, winter will make a chilly comeback in March and last through into April, according to the Daily Express.

The key factor is a change in the North Atlantic Oscillation (NAO), the atmospheric pressure phenomenon which blocked milder weather from reaching Britain before Christmas.

This left Britain prey to a stream of cold from the Arctic, before the NAO changed bringing higher temperatures just before Christmas.

December turned out to be the coldest with temperatures sinking as low as minus 21.1 degrees Celsius in some parts of the country. Many places were brought to a standstill for days by heavy snowfall.

WSI chief meteorologist Todd Crawford said: 'We think that this more atmospherically relaxed pattern will persist well into February, confining any below-normal temperatures to northern regions.'

'At some point later in February or early March, we do expect a return to more strongly negative NAO conditions. At that point, we expect a return to more severe and widespread below-normal temperatures across much of Europe, lasting well into spring.'

The WSI, which provides forecasts for many top US corporations, bases its forecasts on meteorological readings from around the world plus a comparison with similar weather patterns in the past.