(9:30PM - 4/8/21) A storm system will move through the region Friday and Saturday, bringing an isolated severe t'storm threat to Southern Illinois, Friday afternoon through Saturday morning.
A storm system will move through the Midwest and Great Lakes Friday and Saturday, bringing an isolated severe t'storm threat to Southern Illinois, Friday afternoon through Saturday morning. Model guidance has been slowly coming around to showing this potential as the time period in question has approached. With that said, there is some disagreement that exists whether or not there will be a severe t'storm threat across Southern Illinois...But at this time there is enough support to outline a level 1 (isolated) severe t'storm risk.
A marginal environment is expected to develop across Southern Illinois, ahead of an approaching developing storm system. A few isolated showers and t'storms are expected to develop along a stationary boundary across Southern Illinois, and will move across portions of Southern Illinois late Friday morning through late Friday afternoon. With the marginal environment in place, an isolated severe t'storm will be possible...However, the main focus is a bit later, as the developing storm system moves through. Scattered showers and t'storms will develop across portions of Missouri, Arkansas and Eastern Oklahoma Friday afternoon, in the vicinity of a warm front and cold front. This activity will the push northeastward, eventually traversing Southern Illinois from Friday evening through Saturday morning. Given the aforementioned marginal environment that is expected to be in place, a level 1 (isolated) severe t'storm risk will be possible across Southern Illinois, from Friday evening through Saturday morning. Hail, damaging winds and an isolated tornado will all be threats with any severe t'storm.
Below is the severe t'storm forecast for this event.