(8:15AM - 5/27/21) A storm system moving through the region through Friday, will bring the risk for severe t'storms to Central and Southern Illinois, this morning through late tonight.
A storm system that moved through the Plains on Wednesday will move through the Midwest and Mid-Mississippi Valley today, and eventually the Ohio Valley on Friday. This storm system will bring a severe t'storm risk to Central and Southern Illinois, this morning through late tonight. Real time observations continue to support the overall previous forecast, with just minor changes needed.
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.
As expected, a large complex of severe t'storms developed across the Plains last evening. This complex continued eastward overnight, and will be pushing into Northwest and Western Illinois this morning in a much weaker phase. This complex is then expected to push eastward across much of the state this morning and this afternoon, as it continues to overall fade and weaken with eastward extent. However, with a marginal environment expected to develop with time across Central and Southern Illinois, some regeneration is possible. This could lead to an isolated to widely scattered severe t'storm across portions of Central and Southern Illinois, this morning into this 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 along a cold front, across Kansas and Missouri this 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, this evening through later tonight. 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.