Significant portions of the U.S. are expected to be hit by severe weather today, including tornadoes and hail.

“Over 70 million Americans face the threat of severe weather today, with the greatest threat for a significant weather outbreak covering roughly 45,000 square miles, including Chicago metro,” meteorologist Derek Van Dam said in a statement. “All weather modeling points to a significant severe weather outbreak for portions of the Midwest today, with lower chances as you travel south towards the lower Mississippi and Tennessee Valley Region. The threats include tornadoes (a few which may be significant), large to very large hail and severe wind gusts.”

The severe conditions are forecasted to stretch from the central U.S. up through the Northeast and Great Lakes regions. A mixture of unseasonably warm and humid air and an approaching low-pressure system are reportedly to blame for the extreme forecast.

Northern Illinois is most at risk for tornadoes as this system progresses. Indiana, Iowa, and Missouri are classed as “enhanced risk,” while the rest of the Midwest, Ohio Valley, and Southeast regions have a “slight risk.” Across the regions, experts warn of strong, damaging storms with the potential for hail.

“As the storm intensifies and heads toward the upper Midwest, a wind-driven cold rain is expected to spread across the central Plains on Saturday,” the Weather Prediction Center forecasted. “Some of the rain could change over to wet snow Saturday night across the upper Midwest.”

Elsewhere, the Southeast region is expected to experience record high temperatures throughout the weekend, feeling more like summer than early spring. Overall, highs are forecasted to reach up to 20-30 degrees higher than average.

Pictured is a tornado outside Dodge City, Kansas, on May 24, 2016. Brian Davidson/Getty Images