(10:00PM - 5/26/21) A storm system will move through the region tonight through Friday, bringing the risk for severe t'storms to Central and Southern Illinois, Thursday morning through late Thursday night.
A storm system will move from the Plains tonight, through the Midwest and Mid-Mississippi Valley on Thursday, and eventually the Ohio Valley on Friday. This storm system will bring a severe t'storm risk to Central and Southern Illinois, Thursday morning through late Thursday night. Model guidance continues to show this potential, though agreement on specifics for the event has increased.
Model guidance had been showing several potential scenarios for this time period the past several days... However, there had been one solution within model guidance that had been heavily weighed in our previous forecasts. This solution is looking increasingly likely to occur, given continued/increased model support and now real time observational trends support it as well tonight.
The first focus is a complex of severe t'storms that is originating across the Plains this afternoon and evening. This complex is expected to move into the western half of the state by Thursday morning, in a much weaker phase. However, with a marginal environment developing ahead of this complex, some of this activity could remain strong/severe as well as the potential for some regeneration of this activity, which could pose an isolated to widely scattered severe t'storm risk across portions of Central and Southern Illinois, Thursday morning into Thursday afternoon. Damaging winds, hail and an isolated tornado will be the severe weather threats.
In the wake of this initial complex, additional severe t'storm may develop out west across Kansas and Missouri Thursday afternoon. Uncertainty revolves around this potential, in the wake of early day activity. Should this activity develop, it would then push eastward and eventually across Central and Southern Illinois Thursday evening through later Thursday night. A marginal environment will still be in place, which will support an isolated to widely scattered severe t'storm risk. Damaging winds, hail and an isolated tornado will be the severe weather threats.
Below is the severe t'storm forecast for this event.