A wintry mix of ice, sleet, freezing rain and snow will hit the entire Chicago area Wednesday evening, with potentially hazardous travel expected by night time and slick roadways lingering into Thursday morning.
As part of the system, the National Weather Service issued a winter weather advisory for all of northeastern Illinois and parts of northwest Indiana. In LaSalle, Grundy and Kankakee Counties in Illinois and Newton County in Indiana, the advisory will go into effect at 4 p.m., with freezing rain expected, and total ice accumulations around one tenth of an inch.
In all other parts, the advisory will go into effect at 6 p.m., the NWS said, with lower ice accumulations expected to the north. All advisories were set to expire at 6 a.m. Thursday.
"Roads, and especially bridges and overpasses, will likely become slick and hazardous," the NWS warned. "Plan on slippery road conditions this evening."
Winter weather timing
The Wednesday morning commute was expected to remain dry, NBC 5 Meteorologist Alicia Roman said, with a few flurries developing between 9 a.m. and 11 a.m. High temperatures Wednesday afternoon were expected to reach around 32 degrees.
By around 2 p.m., a snow-sleet mix was expected to begin developing, especially in Chicago's southern counties.
Local
Winter weather with ice, snow, freezing rain and sleet was expected to ramp up by 6 p.m., Roman said, with winter conditions overspreading the entire Chicago area from around 8 p.m. through midnight.
Roman noted 6 p.m. through midnight Wednesday was "peak timing" for freezing rain, sleet and icy roads.
Feeling out of the loop? We'll catch you up on the Chicago news you need to know. Sign up for the weekly Chicago Catch-Up newsletter.
"Anything on the roadways could be hazardous," Roman said, "especially during that time -- 8 p.m., 9 p.m., 10 p.m."
Approximate start time of freezing rain and drizzle later today into this evening, plotted on the inset map on the right side of the graphic. #ILwx #INwx (3/5) pic.twitter.com/YAwtnwnGth
— NWS Chicago (@NWSChicago) February 5, 2025
Overnight and into early Thursday morning, lingering freezing drizzle was possible.
"The roadways could still be a little slick out there," Roman said, of the Thursday morning commute.
What is freezing rain?
According to NBC 5 Meteorologist Kevin Jeanes, freezing rain is "just rain," but becomes ice once it makes contact with surfaces.
"Sleet pings, freezing rain clings, that's the difference" Jeanes said. "Freezing rain is some of the worst winter weather you can get. Any bit of ice can cause big problems on the road."
The Chicago area isn't expected to see much ice accumulation from the freezing rain Wednesday, Jeanes said, with only up to .10 of an inch expected. Still, just a glaze of ice, especially on untreated surfaces, could create big travel impacts.
When ice accumulations are higher than that, much dangerous conditions come into play, Jeanes said, as a quarter-inch of ice could lead to isolated power outages and major road hazards.
"Just the weight of the ice on power lines and tree branches alone is dangerous," Jeanes said.
As for Wednesday, Jeanes recommended drivers plan for extra time to travel and to de-ice their vehicles. "Have an ice scraper, and raise windshield wipers before rain starts."
"Don't speed or use hot water to remove ice," Jeanes warned. "And don't start driving until all windows and mirrors are clear of ice."