What's going on with the polar vortex?

Observations show the ring of fierce winds that rotate at the Earth's North Pole has changed direction. Scientists say it's a historic disruption and the earliest reversal on record. What could it mean for the weather?

High up in the atmosphere, there's a ring of cold air swirling over the Arctic that can intensify, weaken, and shapeshift through the seasons. This is the polar vortex. If it gets disrupted, this twisting pool of chilly air can influence the weather we experience, increasing the risk of a cold snap in the Northern Hemisphere.

It's not yet clear how the current disruption to the polar vortex will affect the Northern Hemisphere winter, but scientists agree it is a record-breaking event. "As far as we know, this is the earliest stratospheric vortex disruption that has been observed," European Centre for Medium-Range Weather Forecast (ECMWF) principal scientists Tim Stockdale and Frederic Vitart told the AFP news agency.