TURNING WARMER, MORE STORM CHANCES MIDWEEK

APRIL 27, 2025 -- Clouds and occasional showers have made for a rather cool Sunday across Southern Illinois, but the warmest air of the season (so far) is on the way as we look ahead to the new work week.

On Monday, a warm front will lift to the north and east across Southern Illinois. Warm, humid air will push into the region by Monday afternoon. So far, the warmest temperature of 2025 occurred on April 2 when the temperature peaked at 82-degrees. In the wake of the warm front, temperatures Monday afternoon are likely to warm into the mid 80s.

This warm, humid air surging north will lead to a multi-day severe storm threat across the Midwest.

On Monday, we are NOT expected any thunderstorms in Southern Illinois. However, the threat for severe weather will be focused across the Upper Midwest, with a major tornado outbreak expected across parts of Iowa, Minnesota, and Wisconsin. The Storm Prediction Center has these areas in a Level 4 (out of 5).

By Tuesday, a cold front sagging south into the Mid-Mississippi River Valley will bring the risk for a few severe storms further to the south. Right now, the Storm Prediction Center has all of Southern Illinois in a Level 2 (out of 5). At this time, I am not expecting a major severe weather outbreak in Southern Illinois on Tuesday, but a few scattered severe storms with isolated wind damage and isolated large hail are possible.

Several storms are possible as early as Tuesday morning, especially along the I-64 corridor. Then, during the afternoon, a few more storms may redevelop further south closer to the Route 13.

Tuesday night, it appears the front push south to near the Ohio River, but then lift back north during the day on Wednesday. While Southern Illinois is not outlined for severe storms yet, I think it's possible we see a lower risk for a few strong storms Wednesday afternoon as well.

Then, on Thursday as the larger parent storm system finally tracks into the Upper Midwest, a trailing cold front may trigger a few more thunderstorms Thursday evening across the region.

There could be pockets of heavier rain with these storms, but it will be somewhat scatted with the average for rainfall throughout the week across Southern Illinois between 0.5-1.0".

Cooler, less humid air will move into the region later in the week and into the next weekend.