A potentially dangerous round of severe weather is taking shape across northern Illinois, with the greatest concern arriving Tuesday afternoon and evening.

According to the National Weather Service and Storm Prediction Center, much of the region, especially areas near and north of Interstate 80, is now under an Enhanced Risk (level 3 of 5) for severe thunderstorms.

Storms could begin developing as early as Tuesday afternoon and continue into the overnight hours, with multiple waves possible. The most intense storms are expected from mid-afternoon through the evening.

Forecasters warn that all severe hazards are on the table, including destructive hail larger than 2 inches in diameter, damaging wind gusts, and the potential for a few tornadoes.

“There is potential for very large hail and a few tornadoes, particularly across northern Illinois and southern Wisconsin,” the Storm Prediction Center said in its latest outlook.

In addition to severe storms, repeated rounds of heavy rainfall could lead to localized flash flooding, especially on Tuesday night.

Monday’s weather will serve as a precursor, with scattered thunderstorms possible in the afternoon and evening. While any storms that develop Monday could produce hail and gusty winds, they are expected to be more isolated and less intense, with a lower-end severe threat (level 1 of 5).

Temperatures will remain unseasonably warm through midweek, with highs in the 70s to low 80s, helping to fuel the stormy pattern.

Residents are urged to review their severe weather safety plans now, particularly because storms may occur after dark. Make sure you have multiple ways to receive warnings and know where to seek shelter quickly if a warning is issued.