High in the atmosphere above the Arctic, something strange is happening: the polar vortex has broken down earlier than ever recorded, a phenomenon that can trigger a blast of cold weather in parts of the Northern Hemisphere.
However, there’s also another unprecedented force at work in the form of a historically strong El Niño, which typically drives warmer global temperatures. It’s setting up an atmospheric battle for influence over our weather — and it’s not yet clear which will win.
