A powerful storm system is sweeping across the Midwest, putting millions at risk of tornadoes and flash flooding in what forecasters are describing as a potential “day of destruction.”
The National Weather Service and AccuWeather have warned that roughly 14 million people are in the path of the severe outbreak, which is expected to bring torrential rain, damaging wind gusts and the possibility of numerous tornadoes.
Illinois is emerging as the area of greatest concern, with tornado watches already posted for more than 40 counties across the state.
Meteorologists say Indiana, Iowa, Missouri, Ohio and parts of southern Michigan are also in the heart of the threat zone, while severe thunderstorms could expand into additional parts of the central United States by Wednesday night.
In a statement, AccuWeather Vice President of Forecasting Operations Dan DePodwin said the atmosphere over the Midwest is set up for a dangerous outbreak of fast-moving storms capable of producing widespread wind damage, tornadoes, large hail and flash flooding.
He added that the danger is expected to persist overnight Wednesday as the storm line pushes east into Indiana, far southern Michigan, Ohio and possibly western Pennsylvania.
Several major US cities sit in the middle of a zone meteorologists said will see the greatest chance of a tornado touching down in just hours, including Peoria, Springfield, Bloomington, Decatur and Champaign, Illinois, and Indianapolis, Indiana.
However, the tornado threat in the Midwest also includes moderate risks for twisters in Chicago, St Louis, Cincinnati, Columbus, Dayton, Fort Wayne, Kansas City, Grand Rapids and Detroit.
This is a breaking story. More details to follow.
Pictured: A large tornado moves through Livingston County, Illinois on June 11, 2026
Severe thunderstorm warnings have been issued on June 17 across the Midwest
DePodwin warned: ‘The tornado risk could extend well into the late-night hours on Wednesday across the Ohio Valley.’
The weather expert added that ‘nocturnal tornadoes,’ which describes a twister touching down in the middle of the night, can be the most dangerous events because they are hard to see and can take place when most people are asleep and cannot take cover.
While the chance of a powerful tornado striking a populated city may be the biggest concern on Wednesday, forecasters said this storm is almost certain to bring extremely dangerous thunderstorms, known as supercells.
Torrential downpours, wind gusts between 75 and 85 mph, large hailstones and lightning strikes are expected across an area with more than 40 million residents by nightfall.
‘Dozens of tornado reports are likely with some tornadoes could be particularly intense and on the ground for a long period of time,’ AccuWeather warned.
Flash flood warnings have also been issued by the National Weather Service in eastern Iowa. Meanwhile, flood watches are in effect across parts of Indiana, Kentucky, Michigan and Ohio.
The AccuWeather team noted that the major storm was being fueled by a large area of low pressure in the atmosphere which was ‘unusually intense for June.’
Warm, humid air from the South has also been moving into the Midwest, while the strong wave of low pressure air in the upper atmosphere pushes across the region from the west. This creates a massive clash of different air masses.
One man was dragged from the twisted tornado wreckage after deadly storms killed at least one in Illinois on June 11 (Stock Image)
The greatest chance of a tornado on Wednesday is expected to be in Illinois and Indiana
The warm, moist air acts as fuel for the thunderstorms, making the atmosphere very unstable so the air wants to rise quickly. At the same time, there will be very strong winds blowing at different speeds and directions at various heights in the atmosphere – called wind shear.
The wind shear makes the storms spin and organize into rotating supercells that can stay strong for long periods of time and create tornadoes, wind gusts over 100 mph and large hail that can shatter glass and injure anyone caught outdoors.
Meanwhile, AccuWeather noted that the US was currently seeing a major shift in where deadly tornadoes are mostly likely to touch down each year, with Illinois becoming the heart of a new ‘Tornado Alley.’
‘This year, 145 tornadoes have been reported in Illinois, the most tornadoes of any state in the United States this year. That number is only two reports shy of the state record 147 preliminary reported tornadoes, set in 2025,’ forecasters reported.
It is likely that Illinois will break the state record for tornadoes by Thursday morning based in the current forecasts.
Meteorologists have said the traditional corridor for destructive tornadoes in the South has started moving eastward over the last 40 years.
Known as Tornado Alley, the old hotspot for extreme weather in Texas, Oklahoma, Kansas and Nebraska is now threatening millions each year in states such as Mississippi, Alabama, Tennessee, Kentucky, Arkansas, Illinois, Indiana, Missouri and Iowa.
Illinois has seen the most reports of tornadoes in 2026, a major shift in the traditional ‘Tornado Alley’
Gary Rymek, 65, was rescued from a pile of rubble after a tornado hit his home in Streator, Illinois, on Friday, June 12
