The polar vortex, the often hyped weather feature that typically keeps frigid, Arctic air nestled close to the North Pole during winter, has broken down into 3 pieces. It's spilling cold air out of the Arctic like a leaky faucet and spawning intense winter storms in parts of the U.S. and Europe in particular.
Why it matters: After a relatively mild start to the winter, parts of the Lower 48 states are about to experience a brutal second half to the season, with air temperatures dipping below 0°F as soon as this weekend in the Midwest. If the cold and snow is significant enough, it could put a dent in the economy, which is already feeling the effects of the partial government shutdown.