(9:45PM - 3/26/21) A storm system will move through the region on Saturday, bringing an isolated to widely scattered severe t'storm threat to Central and Southern Illinois, Saturday afternoon through Saturday night.
A storm system will move through the Midwest and Great Lakes Saturday through Saturday night, bringing an isolated to widely scattered severe t'storm threat to Central and Southern Illinois Saturday afternoon through Saturday night. Model guidance continues to be in good agreement regarding all aspects of this potential at this time...Including timing, placement and significance. With this update we have introduced a level 2 severe t'storm threat for portions of Central and Southern Illinois, as confidence has grown.
Scattered showers and isolated t'storms will be possible across Northern Illinois Saturday morning. In the wake of this early activity, a marginal environment develop across a large potion of the state, favoring Central and Southern Illinois. This marginal environment will feature low instability, modest moisture, and good shear and forcing. As a cold front pushes into Northern and Central Illinois during the afternoon, scattered showers and t'storms will develop. This activity will then spread eastward across much of the state, Saturday afternoon into Saturday night. Given the aforementioned marginal environment in place, a low end severe t'storm risk will be possible across much of Central and Southern Illinois, where an isolated to widely scattered severe t'storm is expected. Hail and damaging winds will be the main threats with any severe t'storm, though an isolated tornado can't be ruled out.
Below is the severe t'storm forecast for this event.