The National Weather Service has issued a freezing rain advisory for northeast Illinois that warns of an ice storm that is expected to last until 9 p.m. this evening.
A mix of snow, sleet and freezing rain hit the Chicago area around noon, but there have been no reports of any major accumulation, said Bill Nelson, a meteorologist with the National Weather Service. Still, Nelson warned that a heavy fog will roll in after 7 p.m. tonight and could last until mid to late Monday morning.
According to the agency, the region was going to be hit with freezing rain, possibly mixed with sleet, that will turn to rain as the temperatures rise above freezing in later afternoon or early evening. The agency warns of ice accumulation, up to a tenth-of-an-inch or two, making travel hazardous and possibly leading to downed tree limbs and power lines.
Because the ground is below freezing, the precipitation will freeze on contact, the agency said, leaving sidewalks as well as streets with that potentially dangerous coating of ice.
Forecasters don't expect the storm to have any major lasting effects other than a widespread, dense fog that could pose trouble for drivers once it arrives later tonight.
"We just urge everybody to exercise caution and take things slow," Nelson said.
Much of the ice from today will likely melt as temperatures in the Chicago area reach the mid-30s overnight and slowly increase to the upper 40s by Monday, according to forecasters. Nelson added that it is normal for a heavy fog to appear when cold air is replaced with warmer air and moisture.
Meanwhile, some city and state agencies have already deployed crews to salt streets as the ice storm continues. The city's streets and sanitation department earlier today deployed its full feet of 284 plows to salt main streets, including Lake Shore Drive, and residential roads.
The state's transportation agency has 360 trucks in the northeastern part of Illinois ready to salt roads as soon as precipitation hits the area, said Mike Claffey, a spokesman for the Illinois Department of Transportation.
IDOT will be monitoring weather conditions, but roads will likely be slick this afternoon when the ice storm arrives, Claffey said. He also cautioned drivers to stay off the roads.
"It's going to be very slippery, tricky driving conditions," Claffey said. "If you don't have to be out, you should not be."