Move over, polar vortex. After a couple of years of soul-crushing winters that made the "Star Wars" ice planet of Hoth look like a tropical paradise, Chicago could see a milder winter thanks to a strong El Nino, the weather phenomenon famously spoofed by Chris Farley.

An El Nino occurs when the surface temperatures in the Pacific ocean along the equator are unusually high, thereby causing abnormal weather patterns all over the world. For Chicago, the anticipation of warmer winter temperatures is so strong that local retailers are planning to carry less winter-related items, according to the Federal Reserve’s Beige Book released in September.