What is El Niño and how could it affect weather this year?

Scientists warn a strong El Niño event—dubbed a 'super El Niño'—could trigger extreme weather worldwide this year. The National Oceanic and Atmospheric Administration (NOAA) forecasts an 82% chance of its emergence between May and July, while the World Meteorological Organization (WMO) raises the probability to 90%, with effects lasting until at least November. The last major El Niño, occurring in 2023-2024, was among the five strongest on record, linked to record global temperatures, severe droughts, and intense cyclones. El Niño occurs when weakened trade winds shift warm Pacific water toward the Americas, reversing the usual pattern. Named by 1600s South American fishermen—'the little boy' in Spanish—it disrupts global weather by making dry regions wetter and wet regions drier. The phenomenon typically peaks in winter, though its full impacts remain unpredictable due to overlapping climate factors. In the U.S., El Niño may bring warmer, drier winters in the North and increased flooding in the South, alongside heatwaves nationwide and heightened wildfire risks in the Rockies. Internationally, droughts and fires could worsen in Indonesia, Australia, parts of the Amazon, and Southern Africa, while South America and East Africa may face heavier rainfall. The WMO’s Celeste Saulo notes the event will exacerbate climate change impacts, with U.N. Secretary-General António Guterres calling it an 'urgent warning.' Unlike other weather patterns, El Niño is predictable months in advance, allowing for early preparedness. Climate scientist Tom DiLiberto of Climate Central emphasizes the need for proactive measures despite uncertainties. The last strong El Niño (2015-2016) caused global food shortages and economic losses, underscoring the stakes for 2024.