An intensifying El Niño in the Pacific could lead to a prolonged wet and stormy winter in the UK, potentially reversing the usual trend of late-winter cold.

The current El Niño, which is among the largest on record and continuing to intensify, may alter expected weather patterns across the UK. While typical El Niño events often bring a colder, drier end to winter, meteorologists suggest that a very strong event could result in persistent wet and stormy conditions lasting through the start of spring.

Impact of Strong El Niño Events

Adam Scaife of the UK Met Office notes that while standard El Niño events typically increase the likelihood of cold easterly winds in late winter, very strong events may reverse this trend. Research indicates that powerful El Niños can lead to high pressure in the North Atlantic, resulting in prevailing westerly winds that bring milder, wetter, and stormier air to the UK and northern Europe. This pattern was observed during the 1997-1998 and 2015-2016 El Niño events. Scaife, who co-authored a 2006 research paper on this phenomenon with Thomas Toniazzo of NORCE Research, suggests that this shift is a real effect of strong El Niños. The Met Office is monitoring for this potential pattern as the current event continues to develop.

Environmental and Forecasting Challenges

A prolonged period of wet and stormy weather could saturate UK soils, increasing the risk of flooding, though it would also help replenish reservoirs and groundwater following dry summer conditions. However, predicting these outcomes remains difficult due to the limited number of very strong El Niño events in the historical data record. Separating the specific signal of an El Niño from other weather noise is complex, and long-range forecasting carries significant uncertainty. The World Meteorological Organisation (WMO) reports that the current El Niño is expected to peak in November and persist until at least February 2027, with global impacts including droughts, floods, and extreme temperatures.