Snow, single-digit temperatures and a sub-zero wind chill continue in the Chicago area Sunday morning and show no signs of letting up.As of Sunday morning, just over 1 inch of snow accumulated at O’Hare International Airport and continued to build, according to the National Weather Service. About 2 inches had fallen at Midway International Airport as of 6 a.m.By mid-morning Sunday, 584 flights have been canceled and 354 were delayed at O’Hare over a 24-hour period. At Midway, 108 flights were canceled and 51 were delayed during the same period.More than 11,000 flights canceled as major winter storm bears down across much of the U.S.On the roadways, state troopers responded to 205 crashes — 33 of them with people injured — on Chicago-area expressways from 6 p.m. Saturday to 6 a.m. Sunday, according to the Illinois State Police. Troopers also helped about 71 drivers who called for assistance, according to state police.“Temperatures in the single digits with steady snow is a recipe for very slick, hazardous roads,” the weather service wrote on social media.As of mid-morning Sunday, most of the roads in the Chicago area were at least partially covered in snow or ice, according to the road conditions map from the Illinois Department of Transportation.Steady snow and single-digit temperatures will continue throughout the day Sunday, the weather service said. Wind chills 20 degrees below zero are likely overnight and into Monday morning.Here are the warming centers open Sunday in Chicago:Garfield Center at 10 S. Kedzie, 9 a.m. – 8 p.m.Chicago Public Library locationsChicago Park District locationsChicago Police DistrictsWarming centers open Monday to Friday in Chicago include:Englewood Community Service Center, 1140 W. 79th St., 9 a.m. to 5 p.m.Garfield Community Service Center, 10 South. Kedzie Ave., 9 a.m. to 5 p.m.Dr. Martin Luther King Community Service Center, 4314 S. Cottage Grove, 9 a.m. to 5 p.m.North Area Community Service Center, 845 W. Wilson Ave., 9 a.m. to 5 p.m.South Chicago Community Service Center, 8650 S. Commercial Ave., 9 a.m. to 5 p.m.Trina Davila Community Service Center, 4312 W. North Ave., 9 a.m. to 5 p.m.DFSS Senior CentersChicago Public Library locationsChicago Park District locationsChicago Police DistrictsCity Colleges of Chicago ...read more read less