Predictive Skill of Teleconnection Patterns in Twentieth Century Seasonal Hindcasts and Their Relationship to Extreme Winter Temperatures in Europe

• Published in: Geophysical research letters Vol. 49; no. 11
• Main Authors: Schuhen, Nina, Schaller, Nathalie, Bloomfield, Hannah C., Brayshaw, David J., Lledó, Llorenç, Cionni, Irene, Sillmann, Jana
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 16.06.2022
• Subjects: 20th century; Atmospheric forcing; Atmospheric models; Circulation patterns; Cold waves; energy forecasting; Extreme cold; Extreme low temperatures; Fluctuations; Forecasting; Heat waves; Heatwaves; Mathematical models; North Atlantic Oscillation; Ocean-atmosphere system; Seasonal forecasting; Teleconnection patterns; Teleconnections; Temperature extremes; Weather; Winter; Winter temperatures; Winter weather
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2020GL092360

European winter weather is dominated by several low‐frequency teleconnection patterns, the main ones being the North Atlantic Oscillation, East Atlantic, East Atlantic/Western Russia, and Scandinavian patterns. We analyze the century‐long ERA‐20C reanalysis and ASF‐20C seasonal hindcast data sets and find that these patterns are subject to decadal variability and fluctuations in predictive skill. Using indices for determining periods of extreme cold or warm temperatures, we establish that the teleconnection patterns are, for some regions, significantly correlated or anti‐correlated to cold or heat waves. The seasonal hindcasts are however only partly able to capture these relationships. There do not seem to be significant changes to the observed links between large‐scale circulation patterns and extreme temperatures between periods of higher and lower predictive skill. Plain Language Summary Large‐scale atmospheric patterns that influence European winter weather showed slowly evolving fluctuations over the course of the twentieth century. This affects how well the patterns can be predicted by seasonal forecasting models. However, the impact of the large‐scale patterns on extreme winter temperatures mostly does not change over time, although forecasting models often struggle to correctly predict these impacts. Key Points The predictive skill of winter seasonal hindcasts for teleconnection patterns in Europe varied over the twentieth century Seasonal hindcasts only partly reproduce the links between teleconnection patterns and winter temperature extremes The teleconnection/surface temperature relationships do not significantly change despite fluctuations in predictive skill