Weather Explainers

The Polar Vortex Will Weaken Much Earlier Than Usual; Here's What That Could Mean In December

It has been a warm autumn, so far. But the polar vortex is forecast to change unusually early, and that could impact your weather in December. Here's why.

By Jonathan Erdman • 1 hour ago

What La Niña Means For Your Winter Outlook

The polar vortex is forecast to weaken unusually early, and that could lead to more persistent cold weather in at least parts of the U.S. in December.

Last week, almost 100 daily record lows were tied or broken in the East and South, including some "coldest so early in season" record ties. That cold retreated quickly from most areas.

But there are hints in the atmosphere that the cold may take over, for at least a while.

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