El Niño has officially arrived this year, and the pattern is expected to strengthen through the end of the year. In fact, there’s a 97% chance that it will persists through early spring 2027 and it’s expected to be one of the strongest in decades. While American skiers are used to hearing about El Niño’s effects on snowpack in the Rockies and Sierra Nevada, its influence on Europe’s Alps tends to be far less predictable.
Research published by the European Centre for Medium-Range Weather Forecasts traces the ENSO signal reaching Europe through the North Atlantic Oscillation, the pressure pattern that tends to govern storm tracks and cold air outbreaks across the continent. That research points to a negative North Atlantic Oscillation and Arctic Oscillation pattern, marked by higher pressure over the Arctic and lower pressure at mid latitudes along with weaker eastward winds across the Atlantic, a storm track that shifts south, and a colder signal over northern Europe.
But that relationship is often quite inconsistent. A study released in 2021 in the journal Climate Dynamics found that the ENSO teleconnection to the North Atlantic and European region has weakened in recent decades, shifting after the 1970s from a pattern resembling the North Atlantic Oscillation to one that is orthogonal to it, with the signal becoming statistically insignificant and nearly absent in the most recent decades. Separate research published in the Journal of Climate found that the clearest ENSO related signal in sea level pressure, a pattern resembling the North Atlantic Oscillation, tends to show up specifically in the late winter months of January through March.
A study in Climate and Atmospheric Science complicates things even further. The impacts of El Niño on the North Atlantic and European climate change depending on the time of winter and are not always linear or consistent from year to year, and the paper notes that early winter impacts on Europe have been especially understudied. The same research found that forecasting models do not fully capture how these impacts have shifted over recent decades, even though those models show their own changes in accuracy over several decades.
A related paper in the same journal looked further ahead, finding that the ENSO relationship with the North Atlantic Oscillation normally flips between early and late winter.
For now, NOAA’s outlook does confirm that El Niño will be a dominant global weather driver this winter, but what that means for snowfall in the Alps remains less certain than the picture in North America. The North Atlantic Oscillation, not El Niño alone, stands out as the more direct driver of conditions for skiers in Chamonix, Zermatt, St. Anton, and the rest of Europe.
