The potential is increasing for a significant severe-weather event across northern Illinois on Saturday afternoon and evening.
In its Saturday outlook, the National Weather Service Storm Prediction Center said "a significant severe weather outbreak is possible" with tornadoes, a few which may be significant, large to very large hail and severe wind gusts all possible..
The SPC issued a moderate risk area for western and north-central Illinois, including Dixon, LaSalle and Ottawa. An enhanced risk area includes Joliet and DeKalb, with a slight risk area for the remainder of northern Illinois.
Scattered showers and thunderstorms, a few possibly strong, with the potential for heavy rain will also be possible overnight Friday into early Saturday morning as a warm front lifts north through Illinois.
Temperatures are expected to surge into the 60s Saturday as the warm front, associated with a low pressure system over Iowa, lifts north.
Severe storms could form by mid afternoon near the Mississippi River and race northeast across northern Illinois during the late afternoon and early evening.