More than 5 million people in the United States should prepare for possible nighttime tornadoes

(CNN) – The calendar may be approaching winter, but the weather is set to generate severe thunderstorms from Texas to Ohio capable of producing multiple tornadoes on Friday and late at night, for more than 25 million people.

“Confidence has risen in a more favorable corridor for severe thunderstorms staged from Friday night through early Saturday from approximately the vicinity of the MS River in eastern Arkansas, northern Mississippi northward to parts of the Lower Ohio Valley, “said the Storm Prediction Center (SPC) said Thursday morning.

A level 3 out of 5 “high risk” has been issued for the greater Memphis area, along with Nashville; Evansville, Indiana and much of western Kentucky.

One level 2 in 5 of “slight risk” extends further to include areas along the Mississippi River as well as the Ohio River Valley. This includes Little Rock, Arkansas; Jackson, Mississippi; Shreveport, Louisiana; and Louisville, Kentucky.

The main threats to all of these areas will be destructive winds, hail, and tornadoes.

The “high risk” area has the highest probability of strong EF2-EF5 tornadoes. An EF2 tornado it has winds of at least 178 km / h or more, and an EF5 tornado has winds that exceed 321 km / h.

Forecasters are also concerned that storms are forecast to hit overnight.

“Severe thunderstorms capable of producing multiple tornadoes and scattering numerous damaging winds appear to be likely primarily from Friday night through Friday night in parts of the lower / middle Mississippi Valley to the Lower Ohio Valley and Valley. from Tennessee, “says Spc. “Some of these nighttime tornadoes can be strong.”

When tornadoes occur during the day, people are awake, alert, and make a conscious effort to look for weather alerts. At night when everyone sleeps, that’s a different story.

Nighttime tornadoes are more fatal

Texas averages 140 tornadoes each year, the most of any state. Kansas, Florida, Oklahoma and Nebraska round out the top five.

But the total number of tornadoes doesn’t always tell the whole story. For example, even though Alabama averages 42 tornadoes per year, more than three times fewer than Texas, it ranks first on the list of tornado deaths.

Alabama averages 14 tornado deaths per year, nearly double the next highest, which is eight Missouri deaths per year.

Southern states like Tennessee, Kentucky, and Arkansas also see more tornadoes at night than any other state. This can lead to higher death toll as many people sleep and do not realize a tornado is approaching.

“Tornadoes in the Southeast tend to be more dangerous than their Great Plains counterparts,” says CNN meteorologist Brandon Miller. “There are several reasons for this, some climatic and some geographic. Tornadoes in the southeast often travel faster, driven by a faster jet stream.”

On Friday, severe storms are expected to pass through many of the southern states that are prone to nighttime tornadoes, making alert or warning systems even more essential.

“Friday night is a window of time that everyone should watch closely, have multiple ways to receive weather alerts, and know exactly what your plan of action is in the event that severe weather threatens,” said Thursday the National Weather Service office in Paducah, Kentucky.

Whether you’re using a weather radio, an app on your phone, or any other alert system, make sure the devices are charged and ready to go on Friday.

CNN meteorologists Judson Jones and Monica Garrett contributed to this story.