(11:45AM – Monday, April 21st, 2025) As a few disturbances move through the region, a couple of waves of shower and t’storm activity will traverse the northern half of the state, from Tuesday morning through Wednesday morning. Severe t’storms will be possible with some of this activity.
Timing…
•Tuesday Morning – Wednesday Morning, April 22-23rd.
Location…
•Much of Illinois.
Impacts…
•A level 1 severe t’storm threat is in place across portions of Northern and Central Illinois, for the likelihood of isolated severe t’storms.
•Large hail will be the main threat with activity.
Discussion…
•As a “cold front” approaches, with a low-level jet curving into the region and warm air advection occurring, an initial batch of showers and t’storms may perk up across Southern Minnesota and Northern Iowa tonight into early Tuesday morning. This activity may push into and across portions of Northern Illinois Tuesday morning. An isolated strong/severe t’storm threat will exist with this activity, with hail being the main threat.
In the wake of the potential earlier day activity, a potentially outflow enhanced frontal boundary will lay out west-east across Iowa and Northern Illinois on Tuesday. This boundary will become a focal point for another round of shower and t’storm development on Tuesday afternoon. This activity may congeal into a larger area/cluster, then traversing portions of Northern and Central Illinois from Tuesday afternoon through Wednesday morning. An isolated severe t’storm threat will exist with this activity, with large hail being the main threat.
