The polar vortex is splitting in two, which may lead to weeks of wild winter weather

A dramatic spike in temperatures is occurring at high altitudes above the North Pole, where the air is thin and typically frigid. Known as a sudden stratospheric warming event, experts say it’s likely to have potentially significant repercussions for winter weather across the Northern Hemisphere for weeks to possibly months.

This unusually strong event may have profound influences on the weather in the United States and Europe, possibly increasing the potential for paralyzing snowstorms and punishing blasts of Arctic air, with the odds of the most severe cold outbreaks highest in Northern Europe. The United States is slightly more of a winter wild card for now, experts say, with individual winter storms tough to predict beyond a few days in advance.