A day after widespread storms pummeled the Midwest, with tornadoes tearing through Michigan, more severe weather was expected to hit a large area including Missouri, Illinois and Tennessee on Wednesday.

About 21 million people were under either an enhanced or moderate risk of severe weather — the third and fourth levels of intensity, out of five — on Wednesday, according to the National Weather Service’s Storm Prediction Center.

Here’s what to know about the storms:

• The most intense storms were expected to hit a corridor including the cities of Nashville and Clarksville, Tenn., with about three million people potentially affected by large hail, tornadoes and damaging winds.

• A wider area of about 18 million people from Texas to North Carolina, including the cities of Memphis, St. Louis and Louisville, face an enhanced risk of severe weather.

“Some of the tornadoes may be strong,” the National Weather Service warned in its prediction.

Nearly 50 tornadoes were reported from Oklahoma to Ohio over the past two days, as severe storms wrought damage throughout the Midwest on Tuesday.

The storms brought strong winds and caused power outages. More than 30,000 customers were still without power in Michigan, and 18,000 in Arkansas, on Wednesday morning, according to PowerOutage.us.

Among the hardest hit counties was Kalamazoo, in southern Michigan, where officials said that tornadoes damaged nearly 200 mobile homes and winds were so strong that they lifted some homes away. At least 16 people were injured, the authorities said, though none seriously.

About 50 workers were rescued from a FedEx depot center in Kalamazoo County after a tornado wrecked the building and stranded them inside. The authorities in Oklahoma said a tornado that was up to two miles wide caused widespread destruction on Monday, killing one person in Barnsdall, and damaging up to 40 homes in the small town.

Judson Jones contributed reporting.