(8:00PM - 4/17/21) A storm system is expected to move through the region on Tuesday, bringing the potential for an accumulating snow to the heart of the state.
A storm system will eject out from the Plains Monday night, then moving northeastward through the Mid-Mississippi Valley on Tuesday, and then into the Great Lakes by Wednesday morning. Model guidance has been showing this potential for days. There is spread among possible solutions at this time, however the spread has narrowed with time...with an accumulating snow event looking increasingly possible across the heart of the state.
An area of snow will spread across portions of Northern and Central Illinois, Tuesday morning through Tuesday night. Snow will be of varying intensity during this time, though generally being light to moderate. Given it is mid-late April and temperatures will be marginal, greatest snowfall impacts and accumulations will be on colder surfaces, such as grass.