Polar vortex pattern shift shift signals sudden weather change in US

High above the North Pole, in a largely overlooked part of the atmosphere, a major shift is taking shape. Over the next 10 days, developments in the stratosphere are expected to reshape global weather patterns and may pave the way for a colder, snowier December across sections of the Northern Hemisphere.

Several parts of the United States, currently enduring record-breaking heat just days before Thanksgiving, could soon see a dramatic reversal. Scientists say this could be one of the earliest significant disruptions to the polar vortex since satellites began monitoring it.

At present, temperatures high in the stratosphere — above the layer where everyday weather forms — are rising sharply during a phenomenon known as a sudden stratospheric warming event. Despite the name, the effect at