The ability to predict weeks ahead the onset of a period with severe temperature anomalies is closely linked with the ability to forecast accurately the time evolution of the large-scale atmospheric circulation. Therefore, reliable extended-range forecasts of flow patterns such the NAO and Blocking are instrumental for early warnings of severe cold events over Europe (see Ferranti et al. 2018 for further details)
Introduction:
Further reading:
Ferranti L, Magnusson L, Vitart F, Richardson DS. How far in advance can we predict changes in large-scale flow leading to severe cold conditions over Europe?
Q J R Meteorol Soc 2018;144:1788–1802. https://doi.org/10.1002/qj.3341