The storm pushed into northern Illinois overnight and dumped 3.9 inches of snow at O’Hare International Airport by 6 a.m. Saturday, according to the National Weather Service. Midway International Airport saw 3 inches.

Snow was predicted to fall up to an inch per hour, with 5 to 9 inches expected by the end of Saturday morning north of I-88. Areas south of the interstate could see between 3 and 7 inches.

Drivers faced a dangerous Saturday morning commute, with the worst hazards, including ice-covered roads and gusts up to 35 mph, mainly north of I-88, the weather service said. Saturday morning, the Kennedy Expressway was mostly covered with ice and snow, while the Dan Ryan, Eisenhower and Stevenson expressways were partly enveloped. Road visibility could decrease to a quarter-mile at times.

The storm should taper off by noon Saturday, but additional lake effect snow will occur midday Saturday into Sunday evening, the NWS said.

A lakeshore flood warning was in effect 6 a.m. Saturday until 9 a.m. Sunday, as waves in Lake Michigan could reach up to 10 feet, the NWS said. People were warned to stay away from flood-prone areas, such as piers, jetties and the Chicago bike path trail.

As of midnight Saturday, Chicago’s Department of Streets and Sanitation deployed 287 plows and salt trucks to maintain the streets’ driving conditions, according to a DSS statement. Crews are first working on arterial routes and Lake Shore Drive before moving to residential streets.

Illinois Department of Transportation crews have been pretreating bridges, overpasses, ramps and other road surfaces susceptible to icing before snow starts to fall, the department said in a statement. More than 1,700 plows and salt trucks will be deployed statewide throughout the weekend.

Friday evening, the Chicago Skyway ramp to the Dan Ryan Expressway closed due to weather conditions, IDOT said. It will not reopen until the storm subsides.

Air travel suffered disruptions during the first night of the storm as well. O’Hare reported 456 flight cancelations and 50 delays as of 6 a.m. Saturday, while Midway saw 48 cancelations and two delays, according to the Chicago Department of Aviation.

In anticipation of the snow, Amtrak canceled Saturday service of its Capitol Limited and Lake Shore Limited lines, which connect Chicago to Washington D.C. and New York. A full list of Amtrak service changes can be found on the agency’s website.

While Metra planned to operate trains on a normal weekday schedule on Friday despite the storm, the transit agency advised riders to expect delays, allow extra travel time and refer to Metra’s website or customer alerts for the latest train information.

ComEd officials said crews will be ready to respond to any weather-related power outages the storm may cause.

“Our team is committed to responding to inclement weather issues and restoring any power interruptions as quickly and safely as possible,” ComEd President and Chief Operating Officer Terence R. Donnelly said in a statement.

Nicor Gas officials said residents should use caution when removing snow or ice from gas meters, and call 911 or Nicor’s 24-hour emergency line at (888) 642-6748 to report any gas leaks.

Daytime high temperatures hovered in the upper 20s on Friday and were forecasted to remain so on Saturday. Nighttime Saturday temperatures could plummet to 12 degrees, and only reach as high as 17 on Sunday, the weather service said.

Temperatures could plunge into single-digits Sunday night, with a high near 19 expected on Monday, the weather service said. Wind chills could plummet to 18 degrees below zero over the weekend, with temperatures staying below 20 until at least Thursday.

Chicagoans who need to get out of the cold can call 311 for information about the nearest warming center or overnight shelter. Cook County officials have also released a list of suburban warming centers. State officials also provide information about warming centers online, or at (847) 411-9276.