Severe weather threats coming into focus for Illinois with multiple rounds of storms

Illinois is heading into a two-round severe weather setup that forecasters say could bring damaging winds, large hail, isolated tornadoes and flash flooding to parts of the state from Wednesday night into Thursday night.

The threat is centered on a storm pattern that is expected to first affect parts of central and western Illinois Wednesday afternoon and evening, then strengthen again Thursday evening and overnight. The strongest concern appears tied to the second round.

First round Wednesday

The Telegraph reported that the first wave of storms was expected Wednesday afternoon and evening, with the I-72 corridor under a slight risk and the St. Louis metro under a marginal risk.

The Lincoln, Illinois National Weather Service office said the primary hazard was damaging wind, with gusts potentially above 70 mph. The office also said large hail and one or two tornadoes were possible.

The Telegraph said a 30% severe-wind risk was in place for part of central Illinois, which points to the chance for the strongest storms to produce winds above 75 mph in the higher-risk area.

Forecasters also said the northern part of the state had the higher tornado risk in the overall setup. In addition to wind and hail, individual storms could produce 1 to 2 inches of rain in a short time, raising flash-flood concerns in vulnerable spots.

Stronger round Thursday

The second round is expected Thursday evening and into the night, with an enhanced risk stretching across west-central Illinois and toward the Chicago area.

That is the period forecasters are watching most closely for the most organized severe weather. The broader severe-weather outlook published by the New York Post on June 10 said more than 35 million people in the Midwest were in the Wednesday threat zone, including Chicago and northern Illinois, which it said was under a level 3 out of 5 risk.

That report also said Thursday's system could bring large hail, damaging winds, tornadoes and 1 to 2 inches of rain, with localized 2 to 3 inch amounts in parts of the Midwest.

Flooding concerns

Heavy rain is part of the threat as well. The Telegraph said a flood watch had been issued for central Illinois, while a flood warning was already in effect near the Missouri and Mississippi rivers.

Repeated storms over the same areas could quickly add runoff and worsen drainage problems, especially if heavier cells train across the same corridor. That makes the forecast a concern not only for severe wind and hail, but also for flash flooding.

What comes next

The key question now is how the forecast evolves as the two rounds of storms approach. Forecasters are watching for new watches and warnings, shifts in the severe-wind and tornado corridors, and any expansion of flood watches or warnings.

Residents and local emergency managers in Illinois should keep checking updated National Weather Service guidance through both rounds, especially if they have travel, outdoor events or evening commutes planned.

After the storms move through, the next focus will be storm reports, damage and power outages, along with any new flood warnings if heavy rain repeats over the same areas.