The polar vortex, a high-altitude ring of westerly winds that usually keeps Arctic air locked near the pole, is showing signs of unusual weakening. If that circulation falters or collapses, the result ...

The polar vortex flooding into the US is set to deliver the coldest air on Earth to the northern half of the country, threatening millions with more dangerous winter conditions. Both snow and bitterly ...

The Polar vortex is causing temperatures to plummet dangerously across the Philadelphia region, and frostbite could become a ...