Wegmann, MartinMartinWegmannRohrer, MarcoMarcoRohrerSantolaria-Otín, MaríaMaríaSantolaria-OtínLohmann, GerritGerritLohmann2025-01-082025-01-082020https://boris-portal.unibe.ch/handle/20.500.12422/201226In recent years, many components of the connection between Eurasian autumn snow cover and win-tertime North Atlantic Oscillation (NAO) have been investigated, suggesting that November snow cover distri-bution has strong prediction power for the upcoming Northern Hemisphere winter climate. However, the non-stationarity of this relationship could impact its use for prediction routines. Here we use snow products fromlong-term reanalyses to investigate interannual and interdecadal links between autumnal snow cover and atmo-spheric conditions in winter. We find evidence for a negative NAO-like signal after November with a strongwest-to-east snow cover gradient, which is valid throughout the last 150 years. This correlation is consistentlylinked to a weak stratospheric polar vortex state. Nevertheless, decadal evolution of this link shows episodes ofdecreased correlation strength, which co-occur with episodes of low variability in the November snow index.By contrast, periods with high prediction skill for winter NAO are found in periods of high November snowvariability, which co-occur with the Arctic warming periods of the 20th century, namely the early 20th-centuryArctic warming between 1920 and 1940 and the ongoing anthropogenic global warming at the end of the 20thcentury. A strong snow dipole itself is consistently associated with reduced Barents–Kara sea ice concentration,increased Ural blocking frequency and negative temperature anomalies in eastern Eurasia.en500 - Science::550 - Earth sciences & geology900 - History::910 - Geography & travelarticle10.7892/boris.14577410.5194/esd-11-509-2020