Arctic sea-ice loss fuels extreme European snowfall

The loss of Arctic sea-ice has been implicated with severe cold and snowy mid-latitude winters. However, the mechanisms a direct link remain elusive due to limited observational evidence. Here we present atmospheric water vapour isotope measurements from Finland during ‘the Beast East’—a anticyclonic outbreak that brought heavy snowfall freezing across Europe in February 2018. We find an anomalously warm Barents Sea, 60% ice-free surface, supplied up 9.3 mm d?1 moisture flux this northeasterly airflow. demonstrate approximately 140 gigatonnes was evaporated Sea event, potentially supplying 88% corresponding fresh snow over northern Europe. Reanalysis data show 1979 2020, net March evaporation increased by 70 kg per square metre lost (r2 = 0.73, P < 0.01), concurrent 1.6 (water equivalent) year increase Europe’s maximum snowfall. Our analysis directly links extreme snowfall, signifies 2080, Atlantified will be major source winter for continental