A piece of the polar vortex spills into the Midwest, creating extreme cold for the Chicago area and northwest Indiana for the next few days. For Sunday morning, actual air temperatures will peak early and fall throughout the day.

The National Weather Service has issued a cold weather advisory for the entire Chicago area, taking effect at 6 p.m. Sunday as dangerously cold temperatures move into the region. The advisory is slated to remain in effect until 12 p.