(11:00PM – Saturday, March 28th, 2025) Saturday night update on a storm system that will move through the region, bringing with it rain/t’storms and severe t’storms, which will traverse the state between Sunday morning and Sunday night.
Timing…
•Sunday Morning – Sunday Night, March 30th.
Location…
•Much of Illinois.
Impacts…
•A level 1 to 3 severe t’storm risk is in place across much of the state for the likelihood of isolated to scattered severe t’storms.
•All modes of severe weather will be possible, including large hail, damaging winds and a few tornadoes. The tornado threat will be maximized across Southern Illinois.
•Environmental conditions will be supportive of the possibility of occurrences of strong tornadoes, corridors of widespread/significant wind damage and hail larger than 2.00”.
Update…
•With this update, little changes were needed, as the going forecast is on track.
Discussion…
•As a storm system moves through the region, showers and t’storms will be likely across the state from Sunday morning through Sunday night, with a severe t’storm threat expected with this activity. A weakening line of showers and t’storms will move into portions of Northwestern and Western Illinois on Sunday morning, then progressing across portions of Northern and Central Illinois into midday Sunday. This activity may pose an isolated severe t’storm threat, with hail and damaging winds being the threat. It is likely that re-development of activity will occur during the afternoon along outflow or a trough, as a result of the early day activity, across Eastern Illinois. This activity will pose an isolated to widely scattered severe t’storm threat, with all modes possible. Of greater focus will be across Southern Illinois, roughly from near I-70 on southward. Within this region, ample moisture, instability, shear, and high lapse rates will be in place and juxtaposed to one another. The development of showers and t’storms will likely occur during the afternoon across Southern Missouri and Southern Illinois, along both an advancing cold front and the southern end of a remnant outflow boundary. Scattered severe t’storms of mixed mode (supercells/QLCS) will be likely with this activity, as it traverses Southern Illinois between Sunday afternoon and Sunday night. All modes of severe weather will be likely, including large hail, damaging winds and a few tornadoes. Forecast soundings on weather guidance shows the presence of adequate lower level SRH and nicely looped lower level hodographs, suggesting tornado threat will most definitely be possible. Additionally, environmental conditions will be supportive of the possibility of occurrences of strong tornadoes, corridors of widespread/significant wind damage and hail larger than 2.00”. There severe t’storm threat will come to an end across the state as a whole by around midnight Sunday night/Monday morning.
