Multiple strong tornadoes possible in Illinois, Indiana on Wednesday

Multiple strong tornadoes, including a few intense EF3 tornadoes, are possible across parts of Illinois and Indiana on Wednesday, according to forecasters, who placed the region under a level 4 out of 5 severe weather threat.

The National Weather Service’s (NWS) Storm Prediction Center issued a moderate risk for parts of central and eastern Illinois and western Indiana, including areas near Springfield, Peoria, Decatur, Champaign and Bloomington.

A broader severe weather risk extends across parts of the Midwest, including Chicago, Indianapolis, St. Louis, Toledo and Fort Wayne.

“This area has seen multiple significant severe weather events this year, and unfortunately it looks like it could happen again,” said Evan Bentley, a warning coordination meteorologist at the Storm Prediction Center.

Forecasters said large hail and damaging winds will also be possible, but the tornado threat is driving the higher risk level. The highest tornado probabilities are centered over parts of Illinois, with a surrounding area extending into Indiana where strong tornadoes could also occur.

“That’s where we’re saying we could have the potential for multiple strong tornadoes, potentially even some intense EF3 tornadoes,” Bentley said..

The concern is being driven by an unusually strong wind pattern expected to develop over the region. Bentley said winds in the jet stream could reach 75 to 85 mph over parts of Iowa and northern Illinois, well above what has historically been observed by weather balloons in the area for this time of year.

Forecasters are also watching the low-level jet, with winds of 60 to 70 knots expected about 3,000 feet above the ground. That type of wind shear can support rotating thunderstorms and a higher risk of significant tornadoes if storms develop.

“That is primed for a significant tornado threat,” Bentley said.

The SPC outlook shows more than 2.2 million people inside the highest tornado risk area, with more than 6.6 million people in the broader 10 percent tornado risk zone.

Forecasters urged people across central Illinois, Indiana and nearby areas to have multiple ways to receive watches and warnings on Wednesday.