Yet another blast of frigid temperatures are set to hit the Midwest and Northeast this week, prompting a return of the dreaded phrase "polar vortex."

Temperatures between January 20-25 are typically some of the coldest, but it may be even worse this year as the jet stream nosedives, pumping freezing arctic air to places east of the Rocky Mountains as it dips further south than normal.

But while the coming cold snap is predicted to produce record low temperatures for the second time this month, meteorologists are quashing rumors that this is polar vortex version 2.0.

Actually, they're saying there never really was a polar vortex visit in the first place. NBC cites The Weather Channel in explaining: "The 'polar vortex' is a real weather phenomenon, just not one that actually visits the United States."

The Weather Channel adds the polar vortex is a circular weather pattern that has always been stationed above the arctic.

Think of it as a wheel. When the polar vortex weakens, a spoke of that wheel branches out beyond it's normal circular pattern, releasing a powerful chill like the one we saw earlier this month.

But, the polar vortex itself never actually descends into our latitude.

The Washington Post says the coming arctic blast may not be as cold as earlier this month, but that "this cold wave may be more memorable for its persistence, rather than its intensity."

In several areas of the country, once temperatures hit freezing Tuesday, they are expected to remain that low for more than a week and a half.

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