Over 1,400 flights have been canceled nationwide with the majority due to weather hitting the upper Midwest, according to FlightAware.

Chicago O’Hare International Airport is the most impacted airport by far, with over 930 cancellations and over 750 delays as of Saturday afternoon. Flights leaving to O’Hare are delayed an average of five hours due to snow and ice, according to the FAA.

Chicago Midway International Airport has 187 cancellations and 85 delays. Both airports have been issued ground stops.

The heaviest snow in Chicago is expected Saturday between 12 p.m. and 8 p.m.

The snow becomes lighter overnight into Sunday morning, with some lingering snow winding down by 12 p.m. Sunday. Between 6 to 10 inches of snow are possible.

A cross-country storm already brought snow from Montana to Missouri later Friday. The storm has begun to move into parts of the Midwest Saturday morning, impacting travel for millions making the journey back home from the holiday.

Winter weather alerts are up for millions ahead of this system from North and South Dakota down to Indiana and Michigan.