|Probability of any severe weather|
Tomorrow, high instability combined with humid air and high temperatures will make for a potentially intense day in northern Illinois, southern Michigan, and eastern Iowa.
Current indications are that isolated storms will pop up and quickly transition to clusters of storm systems that will be sweeping the area. The clusters may have the most impact on the 30% and hatched areas. For future reference, a hatched area represents a 10% chance of a 'significant' severe weather occurrence (large hail, extreme winds, etc.).
I am within this slight risk area and will try to get pictures if I am able to.