More than 1,600 flights were canceled Sunday and more than 3,600 delayed out of St. Louis and the Chicago area as a major winter storm approaches the midwest, according to data from Flight Aware.

The details: The cancellations are mostly concentrated in the Midwest with Chicago O’Hare airport experiencing more than 700 alone. A blizzard warning was issued by the National Weather Service which explained that a "[s]ignificant winter storm will bring heavy snow and some blizzard conditions from the Middle Mississippi Valley to the Great Lakes through Monday."