Forecasters are warning about severe weather that could bring multiple rounds of thunderstorms spanning hours, along with potential tornadoes, to the northern Illinois area on Tuesday.
The National Weather Service (NWS) said Tuesday will be a day to be “weather aware” in Illinois.
There will be a threat for multiple rounds of severe storms in the general area from late afternoon through the overnight hours into Wednesday morning.
All hazards, including tornadoes, destructive hail, damaging winds, and flash flooding, will be possible, the NWS said.
The threat of tornadoes will be highest near a warm front. Warm fronts often stall near or just south of the Interstate 80 corridor around this time of year, the NWS said. “This aspect of the forecast will be a key focus going forward.”
The main threats north of the warm front will be destructive hail and flash flooding.
The NWS said there will be multiple rounds of storms, lasting potentially over the span of a 6-12 hour period in some locations. Adjustments in the forecast are likely.
Cooler conditions arrive on Wednesday and another system will bring a chance for showers and potentially very windy conditions Thursday evening into Friday.
The NWS said Monday that the Chicagoland is currently at a level two and three out of five for severe weather threat for Tuesday.
“All severe hazards, including tornadoes, large to destructive hail, damaging winds, and flash flooding are possible. The main threat for tornadoes exists mainly south of I-80,” the agency said.
The most intense severe storms in the state could produce destructive winds over 70 mph with hail greater than two inches. Torrential rainfall may cause flash flooding of roads, low-lying areas, fields and basements while causing rapid creek rises.