El Niño Potentially Linked to Unprecedented Early Polar Vortex Breakdown, Raising Concerns for Winter Weather
The polar vortex, a high-altitude band of westerly winds circling the Arctic, experienced an unprecedented early breakdown on November 10, with winds reversing direction. This event is the earliest recorded since the 1950s, beating the previous record by 18 days. While such collapses occur every few years, their occurrence in November is highly unusual. Scientists, including Adam Scaife at the Met Office, suspect a potential link to the exceptionally strong El Niño climate phase. El Niño typically strengthens the vortex in autumn and early winter before weakening it in late winter, allowing cold air to spill southwards. The current El Niño has already warmed tropical Pacific surface waters to record temperatures. The mechanism proposed involves El Niño-linked waves in the jet stream propagating upwards into the stratosphere, where they can crash into and weaken the polar vortex by pushing against its flow with easterly momentum. However, other factors, such as a high-pressure blocking system over Scandinav...
