The weather service is warning about a severe weather threat involving thunderstorms that could bring damaging hail and winds to the Chicagoland area Friday evening.
The National Weather Service (NWS) issued a hazardous weather outlook for northeast Illinois on Friday morning.
The outlook includes Lake, McHenry, Boone, Will, Cook, Winnebago, Ogle, Lee, DeKalb, Kane, DuPage, LaSalle, Kendall, Grundy, Kankakee, Livingston, Iroquois and Ford counties.
The outlook said southwest winds will gust to around 40 mph from late Friday morning through early Friday evening.
Scattered thunderstorms are expected to develop on Friday evening.
Some of the storms could be severe with large hail, possibly up to two inches in diameter, being the greatest threat.
The outlook said there is also the potential for locally damaging winds and possibly a tornado, especially if thunderstorms become more widespread and are able to organize into a line.
The damaging winds could bring down tree branches or move outdoor objects.
The outlook area is expected to see the greatest threat from 7 p.m. and 12 a.m.
Residents are advised to move indoors if they hear thunder and have multiple ways to get weather warnings, the NWS said.
The NWS said late Friday morning that there is a likelihood of cooler temperatures than previously forecast across far northern Illinois, mainly the state line counties, and especially for the Lake County lakeshore.