54 million people at severe weather risk as tornadoes, large hail threaten cities across US

More than 54 million people are at risk of severe weather in the Midwest on Tuesday, including major metropolitan areas such as Chicago, Indianapolis and Detroit, as a powerful cross-country storm tracks east.

Tuesday morning is expected to remain on the quiet side, but as the day continues, the atmosphere will become more unstable with moisture streaming in from the south ahead of a powerful cold front moving in from the west, as well as the lack of cloud cover during the day.

“We’ve got the clouds for the initial stuff,” FOX Weather Meteorologist Bob Van Dillen said. “We thought maybe that would disrupt the instability later this afternoon, but the clouds are south of central and northern Illinois, which means you’re going to see a lot of daytime heating today, and that’s going to make it even more unstable for you later this afternoon.”

The moisture being pulled in from the south will push farther north all the way into parts of southern Michigan. Typically, at this time of year, moisture needed to fuel a severe weather threat is confined to areas along the Gulf Coast and Deep South, but that’s not the case with this rare February threat.

Tornadoes, large hail possible on Tuesday in Midwest, Great Lakes

The explosive development of thunderstorms expected during the day and into the evening and overnight hours on Tuesday is also being fueled by record warmth ahead of the cold front, as well as a blast of cold air behind it.

“The type of situation we have now, we have that huge cold front coming in with massive temperature drops,” Van Dillen said. “So, the lapse rates, as you go up through the atmosphere, the way it cools down, the quicker, the more unstable, and that’s what we’re going to find.”

That’s why large hail will also be a concern with any storms that do develop.

“And that’s because we have the cold air aloft,” FOX Weather Meteorologist Britta Merwin said. “I mean, these updrafts, these storms are going to build vertically. And so these hailstones are going to have the opportunity to really touch on some cold air.”

Nearly 55 million people from northeastern Arkansas to the Ohio Valley and southern Great Lakes are at risk of severe thunderstorms starting late Tuesday afternoon.

However, NOAA’s Storm Prediction Center (SPC) has placed more than 38 million people in a Level 2 out of 5 on its 5-point severe thunderstorm risk scale.

This area stretches from eastern Missouri to Ohio and southern Michigan and includes major cities such as Chicago, Indianapolis and Detroit. Other cities in that risk include Louisville in Kentucky and Cincinnati, Columbus and Cleveland in Ohio.

St. Louis had been in a Level 2 risk over the past few days, but the latest update from the SPC showed the city being dropped to a Level 1 risk. Pittsburgh and Milwaukee could also see severe weather, but they, too, have been placed in a Level 1 out of 5 risk.

Forecasters said there is the threat of tornadoes, large hail and damaging wind gusts with any thunderstorms that develop through Tuesday night.

Those threats extend from eastern Missouri to Ohio and southern Michigan.

However, there is a hatched area where there is a higher threat for hail of at least 2 inches in diameter across portions of eastern Missouri, Illinois, Indiana, southern Michigan and northwestern Ohio.

Sometimes, the SPC uses a black-shaded area called a “hatched area.”

A “hatched area” means there is a significant threat of the particular type of severe weather being described in the associated map inside the highlighted area.

Severe thunderstorms possible in Appalachians on Wednesday

The SPC has also highlighted an area of the central Appalachians that is at risk of seeing severe weather on Wednesday morning.

While, so far, the risk is low, severe thunderstorms are possible for cities such as Lexington, Hazard and London in Kentucky, as well as Charleston, Parkersburg and Beckley in West Virginia.