Why El Niño is likely to make for a turbulent winter in the northern hemisphere

El Niño is a climate pattern that forms over the Pacific Ocean every few years. It’s characterized by warmer-than-average sea surface temperatures and it affects weather patterns around the world. Experts say the current El Niño is set to be both strong and persistent. It’s likely to intensify over the winter, too. With sea surface temperatures already breaking records this year the northern hemisphere could be facing a winter of extreme weather.