Multidecadal variability of the ENSO teleconnection to early-winter temperature in Europe

El Niño-Southern Oscillation (ENSO) is the main mode of climate variability at interannual timescales, impacting the climate of many regions worldwide through atmospheric teleconnections. Characterising these teleconnections is relevant to improve seasonal prediction skill over the regions affected by ENSO. However, the early-winter (November-December; ND) North Atlantic and European (NAE) atmospheric circulation response to ENSO and its associated impacts on surface air temperature in Europe remain unclear. Hence, the ENSO early-winter teleconnection to temperature in Europe is analysed in this study. Unlike most of the previous studies addressing this teleconnection, our analysis is carried out in different time periods, taking into account the climate shifts that occurred in the Pacific in the 1970’s and in the 2000’s. This fact allows for the possibility of a non-stationary teleconnection due to changes in the mean circulation. The study also aims at analysing the ability of the European Centre for Medium Range Weather Forecasts’ (ECMWF) seasonal forecast system System 5 (SEAS5) to reproduce the ENSO early-winter teleconnection. Results show that ENSO has a significant impact on the early-winter temperature in Europe, with a clearly non-stationary behaviour of the teleconnection. Between the 1950s and mid-1970s, impacts on temperature were restricted to the far north of Europe, and since the late 1970s, they have extended to much of the rest of Europe, with the largest impact since the 2000s being located in the southwest. In this region, ENSO shows significant correlation with the leading mode of seasonal early-winter temperature variability. These changes are related to interdecadal changes in the ENSO wave train pattern that reaches the NAE region. ECMWF’s SEAS5 captures reasonably well the spatial pattern of the teleconnection, although with a notably weaker signal compared to observations. Overall, these results may contribute to enhance early-winter seasonal predictability over Europe.