If you live in America, odds are you didn't wake up to anything near a white Christmas.
Temperature records around the U.S. were shattered on Christmas Eve, with some cities like Baltimore seeing highs up to 30 degrees Fahrenheit warmer than normal.
So what's up? It all links back to the polar vortex, the surge of cold air that hit the U.S. several winters ago, causing temperatures to plunge far below zero.
A band of cold air called the "Arctic Oscillation" surrounds the northern latitudes of the globe. Usually, the oscillation spins quickly and traps most of the cold air around the pole, but sometimes the band will slow and some of that cold will slip downwards, which is what happened during the polar vortex.
The opposite is happening now, and that oscillation is moving far faster, keeping all the cold air trapped north and making temperatures in parts of America warmer, according to the National Weather Service.
The bizarre swings have obliterated long-held records, and places like Albany, New York -- usually blanketed under snow -- were warmer than Phoenix at 72 degrees. That temperature beat the old record of 57 degrees set in 1941.
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