The polar vortex is forecast to change early: What that means for the winter ahead

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.
What is the polar vortex: Almost 12 years ago, the "polar vortex" entered into pop cul