Global Warming - The Polar Vortex

Climate Central: What Happened to the Polar Vortex?

When the polar vortex is strong, as it is now, it keeps arctic air fenced in. That is part of what is currently keeping the weather so mild in the eastern U.S.. But when the vortex is perturbed or weakened, the jet of air becomes more wobbly and can set up southward excursions of frigid air — what we saw plenty of times over the last couple winters...