A “multi-faceted” weather system is expected to bring heavy rain Wednesday followed by approximately 3-6 inches of snow to Lake and McHenry counties, the National Weather Service said.
Heavy rainfall is expected to begin Wednesday evening into Thursday morning, with the heaviest south of a Chicago to LaSalle Peru line.
Some areas of the Chicago area could see 1-2 inches of rainfall, leading to possible flooding. In Lake and McHenry counties, rainfall of half an inch to one inch is expected.
Rain will change to an icy mix of freezing rain and some sleet then snow Wednesday night into early Thursday.
The National Weather Service (NWS) said this will make travel “very hazardous.” Some ice accumulation is likely.
The NWS said they are more uncertain about a swath of heavy snowfall totals along with strong winds from the north.
“Confidence remains on the lower side in the snowfall forecast, though the current forecast favors somewhere in the orange shaded area for a swath of snowfall amounts of 6″ or more,” the NWS said.
Meteorologists in a graphic painted Lake and McHenry counties and the Chicago area in orange, meaning a “medium” threat for six inches of snow or more.
In an expected snowfall forecast, the NWS said Lake County is likely to get 4-6 inches of snow while McHenry County could see 3-4 inches of snow.
A hazardous weather outlook was issued for much of northern Illinois Tuesday morning in anticipation of the arriving winter weather.