The weather service is warning about strong to severe thunderstorms expected Thursday afternoon into the evening that could bring tornadoes, damaging hail and damaging winds to the Chicago area.
The National Weather Service (NWS) issued a hazardous weather outlook on Wednesday afternoon for Lake, McHenry, Will, Cook, Boone, Winnebago, Ogle, Lee, DeKalb, Kane, DuPage, LaSalle, Kendall, Grundy, Kankakee, Livingston, Iroquois and Ford counties.
The outlook said gusty southwest winds and dry conditions would lead to a heightened grass and brush fire danger on Wednesday afternoon.
Scattered thunderstorms were expected on Wednesday evening, mainly well south of Interstate 80.
The strongest storms will produce brief heavy downpours and hail, possibly up to around an inch in diameter.
The outlook said thunderstorms will likely develop on Thursday afternoon and will linger through the evening hours on Thursday, especially well south of Interstate 80.
“Conditions appear favorable for severe thunderstorms capable of producing hail potentially larger than 2 inches in diameter. In addition, there will be some threat for locally damaging winds in excess of 60 mph,” the outlook said.
The most intense severe storms have the potential for a “few” tornadoes, mainly near and south of a line from Streator to Rensselaer, along with very large hail, potentially two inches or more in diameter.
The NWS said the severe weather comes amid a sharp cold front dropping into the area.
The primary concerns with storms are very large hail and damaging wind gusts, the NWS said.
The thunderstorms are expected to begin around 1 p.m. and intensify into the afternoon and evening as the temperatures drop quickly.
Residents are urged to move indoors when they hear thunder and have multiple ways to get weather warnings, forecasters said.