(10:45PM - 10/23/21) A storm system moving through the region will bring severe t'storm potential to portions of the state, early Sunday morning through late Sunday night.
A storm system move from the Plains on Sunday morning, into the Mid-Mississippi Valley and Midwest by Sunday night, and into the Great Lakes and Ohio Valley on Monday. This storm system will bring severe t'storm potential to portions of the state, early Sunday morning through late Sunday night.
Sunday Morning - Sunday Night, Oct 24th...
Widespread areas of rain and t'storms will spread across much of Northern and Central Illinois, from late tonight/early Sunday morning through late Sunday afternoon. With a warm front expected to be meandering across Central Illinois and an associated marginal severe t'storm environment, an isolated severe t'storm will be possible across Central Illinois early Sunday morning through mid Sunday afternoon.
The main focus will come a bit later, as scattered showers and t'storms that develop along and ahead of a cold front across Southern Iowa and Missouri Sunday afternoon will sweep eastward, making it to the Missouri/Illinois border by late Sunday afternoon or early Sunday evening, and then spreading across Central and Southern Illinois late Sunday afternoon through Sunday late night. Ahead of this activity, the environment across the state will be supportive of some severe t'storm threat. This environment will feature low instability of 500-2,000J/KG, dew points in the low to mid 60's, good forcing, and lapse rates of 5.5-7.0C. This environment will be supportive of upwards of a level 1/isolated to level 2/sporadic severe t'storm risk across Central and Southern Illinois. Damaging winds, hail and isolated tornadoes will be the severe weather threats.
Below is the severe t'storm forecast for this event.