10/11/2011 10:28 GMT | Updated 08/01/2012 05:12 GMT

Seasonal Forecasters Are About Two Years Late Predicting 'Cold European Winter'

What do you mean, "cold winter ahead"? Britain and other parts of Western Europe are not at all likely to experience the prolonged cold easterlies of recent winters. Judging by the Sun, we'll have to wait at least another six years or so. Meanwhile: rain.

In the UK, Germany and for instance the Netherlands there has been ample media coverage of different weather agencies predicting a cold winter 2011-2012, another cold winter that is. Over the coming months high pressure systems would prevail over Northern Europe, blocking a wet and mild Atlantic influence and allowing easterlies to bring cold (and drier) winter conditions.

That would be a repetition of the three most recent winters (which brought beautiful scenes of ice skating and white Christmases - next to massive traffic jams and air flight delays) with the big exception that theory backs up these past three relatively cold winters, whereas it does not support a fourth edition of snow and frost.

Bits of theory and observations

The theory, as shown in the infographic of the European winter forecast, is quite straightforward - and has been known to climatologists for many years: during the winter months solar activity influences air pressure patterns over the Arctic.

Especially the number of sunspots is key. When there are few, northern hemisphere westerlies are weaker - and cold air is capable of escaping from the Arctic towards for instance the USA and Europe. Specific conditions in Britain depend most on what is known as the North Atlantic Oscillation (NOA) - the air pressure difference between Iceland and the Azores. During a solar minimum, the NAO index tends towards a negative phase, with fewer depressions around Iceland. That means the UK has less wind blowing in from the southwest, so less rain. In such a case high pressure can settle over Scotland or Scandinavia, allowing for wind to blow in cold and dry air from the east.

New research by a team of British scientists led by the Met Office Hadley Centre and published last month in Nature Geoscience has reconfirmed this link between solar activity and European winter weather. Climate models can now reproduce it - but you can also check temperature datasets to find a strong correlation stretching back well into the 20th century. In fact, in recent decades Britain has not experienced one single cold winter that did not fall into the minimum phase of the 11-year sunspot cycle.

Perhaps these European winter forecasters somehow experience a phase difference, but NASA observations show we've already had this century's first sunspot minimum and with the winter of 2011-2012 we are well on our way towards the new maximum, which is forecast for 2013.

Good news for the Arctic

Although this would imply we would not have much snow and ice to play around with, it would actually be good news for the Arctic. The North Atlantic Oscillation is closely linked to the Arctic Oscillation - an air pressure pattern centred on the North Pole. If the increasing number of sunspots would bring the Arctic index into 'a positive phase' as well, then temperature isolation of the High North would improve compared to recent years. In these last few years there were record-high temperatures over Greenland and the Arctic Ocean - and last year we had the smallest winter ice extent on record. So let's ignore our own rainy Christmas and hope this winter season weather conditions will at least favour some extra sea ice recovery over the pole.