Ice Storm Timeline: When Freezing Rain, Flooding Will Hit Chicago Area

ILLINOIS — Some parts of the Chicago area are under ice storm warnings and winter weather advisories on Wednesday as freezing rain, icing, rain and high winds approach.

An ice storm warning is in effect for McHenry County until 6 a.m. Thursday, according to the weather service. Significant icing is expected, with ice and sleet accumulations up to a half inch. Power outages and tree damage are likely.

Related: 2 McHenry Co. School Districts Announce Closures Wednesday

Northern Cook, DuPage and Lake counties are under winter weather advisories until 6 a.m. Thursday as well. Those areas could see some freezing rain, with ice accumulations of one to two-tenths of an inch, according to the weather service.

For areas outside the advisories, including Chicago and south of the city, heavy rainfall is the main threat, especially Wednesday afternoon, according to the weather service.

Localized flooding is possible, as well as thunderstorms, the weather service said.

AccuWeather predicted 1.41 inches of rain for Joliet on Wednesday, which includes nine hours of precipitation. The private forecaster said it will be "increasingly windy with rain and a thunderstorm."

Winds will also increase across the area on Wednesday, and stronger winds of 40 to 45 mph are expected on Thursday, the weather service said. Thursday has a high of 49 for areas northwest of I-55, and a high of 58 for areas southeast of I-55.

Historic Winter Storm Snarls Travel, Slams Midwest With Snow, Ice

The timing of the severe weather will likely create a treacherous evening commute. After rain, and sleet develop through the morning, the afternoon will likely bring accumulating ice for the northern suburbs and heavy rain to the south, NBC Chicago reported.

By Wednesday night, rain and sleet will taper off, but wind gusts of up to 35 mph are possible for some parts of the Chicago area.