Winter 2009 forecast for Europe

Summary: There is a relatively high degree of confidence that the winter of 2009 will be much colder than the winter of 2008, particularly in Scandinavia. The mean winter temperatures will also likely be below the averages for the past ten years over northern and central Europe. The temperatures are forecast to be near or slightly below the 1971-2000 averages for much of Europe.

Fig. 1. Surface air temperature forecast for the winter (DJF) of 2009 in Europe.  The blue (red) contours and the letter C (W) indicate colder (warmer) than normal temperatures. CL means near normal. The base period for calculating anomalies is 1971-2000. The numbers at the contours are confidence factors of the forecast.

Discussion

The forecast of an anomalously cold winter in Europe is primarily due to a negative phase of the North Atlantic Oscillation (NAO) pattern expected during the winter of 2009 (see the forecast for the North Atlantic). The negative phase of the NAO is associated with anomalously cold winter over much of Europe, particularly in Scandinavia. A meridional type of atmospheric circulation, with positive 500-hPa height anomalies over the high latitudes and a negative 500-hPa height center over the eastern North Atlantic (a pattern similar to the negative NAO phase), is suggested by rule 288.

The forecasts for individual cities are in agreement with the temperature anomaly distribution that can be inferred from the above circulation patterns. For example, the forecast for London uses rule 462 that links the winter temperatures with solar activity. When solar activity is low, the odds are about 2 to 1 in favor of a cold winter in London.

Using a simple extrapolation technique, a decrease in winter temperature in Stockholm from the last winter can be forecast with a high degree of confidence. A similar forecast can be made for central Europe. 

There are several rules that calls for a colder than normal winter in Madrid. Rule 448, for example, links temperature in Madrid with the distribution of summer sea-surface temperature in the North Pacific. Rules 449 and 452 show a decadal scale cooling in Spain during the period from 1999 to about 2014.

As for other publicly available forecasts, the U.K. Met Office cautiously predicts that “winter temperatures are more likely to be either near, or above average, than below average over much of the European region. For northern Europe, including the UK, Winter 2008/9 is likely to be less mild than last winter.” The forecast produced by the CFS model shows above normal temperatures over the British Isles, Scandinavia and eastern Europe. For the rest of Europe, the temperatures are forecast to be below normal.

Recommendations for trading at Weatherbill.com

The best bets are for temperatures below the past 10-yr average in Berlin (and other German cities) and temperatures below the 1971-2000 average in Madrid.