Despite a week of bitter cold temperatures, central and western Europe has had a relatively mild winter this year.
Other parts of the northern hemisphere, however, have not been as lucky. For example Southeastern Europe, Central and Eastern Asia have seen massive waves of bitter cold and heavy snow. Climate Depot here tallies up the damage.
Now there are emerging indications that central and western Europe may need to brace for more bitter cold and treacherous winter conditions starting in early February.
German weather and climate analysis site wobleibtdieerderwaermung here writes that leading models are looking at a sudden stratospheric warming (SSW) over the Arctic over the coming days, which in turn will very likely lead to another powerful cold wave this winter for Western and Central Europe.
The German site writes that currently calculations for the stratosphere at approx. 30 km altitude appear as follows:
ECMWF projection for pressure (geopotential) and temperature of the upper stratosphere from 23 January – 1 February 2016. Source: www.geo.fu-berlin.de/met/ag/strat.html.
The wobleibtdieerderwaermung site writes (my emphasis):
An SSW will cause the polar circulation to become disrupted and possibly even split. This process in the stratosphere also causes the circulation in the troposphere over the entire northern hemisphere to be changed: The westerly drift over the north Atlantic gets interrupted by a blocking high pressure region and allows polar air to flow in over central and western Europe from the north and east.”
There is a large body of literature out there showing strong links between low solar activity, stratospheric warming and cold European winters.
The wobleibtdieerderwaermung site writes that both models of the ECMWF and NOAA/GFS agree that most likely there will be strong westward drift over the North Atlantic to Central Europe in late January 2016.
ECMWF prognosis for the Arctic polar circulation 150 hPa from 23 January to 31 January 2016. The polar circulation is strongly disrupted and is dipolar. The core of the larger southern circulation lies over northern Norway and shows a strong westerly flow that leads us to expect unsettled weather. Source: www.geo.fu-berlin.de/met/ag/strat.html.
GFS prognosis for the Arctic polar circulation 100 hPa (16,000 0m) from 24 January to 3 February 2016. The polar circulation is strongly disrupted and is dipolar. The core of the larger, right circulation lies off northern Norway and shows a strong westerly flow that leads us to expect unsettled and stormy weather. Source: www.cpc.ncep.noaa.gov/products/stratosphere/emcz.
The pattern, the German site writes, will deliver lots of snow at the higher elevations in Germany, especially in the Alps. Moreover a strong westerly drift is a good sign for a split of the jet stream. The site wobleibtdieerderwaermung writes that should the model prognoses come true, then the chances are good for the third cold snap of the 2015/16 winter in western and central Europe.
Naturally there’s a lot of speculation and uncertainty involved in forecasts beyond a week, sometime even those beyond just a few days. If one thing is certain, it is that Europe’s weather never fails to deliver surprises.