An Abrupt Temperature Change Could Bring Hail and Tornadoes to the Midwest

“Record-shattering warmth” followed immediately by frigidly cold weather will create the opportunity for hail the size of hen eggs and possible tornadoes in the Midwest on Tuesday evening into Wednesday morning. Chicago, St. Louis and Indianapolis all have some risk of severe storms, and residents there are also expected to experience an abrupt return to wearing multiple layers after days of short-sleeves weather.

In St. Louis, the temperature is likely to drop by 40 to 50 degrees, and forecasters warned severe storms may threaten the area on Tuesday. Severe storms are typically more common in the South during February but are not unheard-of in the Midwest. On average, about one tornado occurs each February in Indiana, two in Illinois and two in Missouri.

The weather setup has some of the hallmarks of noteworthy severe weather events, forecasters said. However, a few things are still unknown, like how much moisture will surge north out of the Gulf of Mexico. That creates some uncertainty about how strong these storms will be.

Here are the things to know.

• The exact locations that will be most affected by the severe weather are still unknown. They are most likely to occur between Missouri and Michigan, primarily across northeastern Illinois and northern Indiana, where there is an increased risk for two-inch-thick hail and tornadoes.

• Temperatures may plummet as much as 40 degrees or more after the severe storms pass through Tuesday night into Wednesday morning.

Before the storms, high temperature records may fall.

Tuesday into Wednesday will be a “tale of two seasons,” forecasters in Chicago said. More than 50 daily record high temperatures could be broken across the central portion of the United States on Tuesday as high temperatures reach 30 to 40 degrees above normal.