What meteorologists call El Niño — a warming of surface waters in the central and eastern tropical Pacific Ocean — can alter weather patterns around the globe. BBC meteorologist Matt Taylor looks ahead to the autumn and winter months to consider whether the current El Niño event will increase the chance of snowfall in the UK.
How El Niño works
El Niño changes the distribution of heat and atmospheric pressure across the tropical Pacific, which in turn can nudge the position and strength of the jet stream and other large-scale circulation features. Those shifts can have knock-on effects on storm tracks, temperature and precipitation patterns in distant regions, but the signal that reaches north-west Europe is often weaker and less direct than in other parts of the world.
Other drivers matter more for UK winters
Forecasters emphasise that the North Atlantic Oscillation (NAO), the Arctic Oscillation and conditions in the North Atlantic are typically stronger determinants of UK winter weather. For example, a persistently positive NAO tends to be associated with milder, wetter conditions across much of Britain, while a negative NAO can favour colder conditions and heighten the chance of snow in eastern and inland areas. Those modes of variability can either reinforce or counteract any influence from El Niño, making seasonal outcomes hard to predict far in advance.
What to expect this autumn and winter
Seasonal outlooks from weather centres combine many models and indicators, and they are updated as the season approaches and new data arrive. While El Niño may contribute to a tendency in the broader circulation, it does not on its own guarantee a snowy winter for the UK. Local snowfall will depend on the timing of cold Air outbreaks, Atlantic storm tracks and regional temperature contrasts, all of which forecasters will continue to monitor closely through the coming months.