The calendar may be nearing winter, but the weather is set to serve up severe thunderstorms capable of producing several tornadoes on Friday and into the overnight hours, for more than 25 million people from Texas to Ohio.
“Confidence has increased in a more favorable corridor for organized severe thunderstorms Friday night into early Saturday morning from roughly the vicinity of the MS River in eastern Arkansas and northern Mississippi northward into parts of the lower Ohio Valley,” the Storm Prediction Center (SPC) said Thursday morning.
A level 3 out of 5 “enhanced risk” has been issued for the greater Memphis area, along with Nashville; Evansville, Indiana, and much of western Kentucky.
A level 2 out of 5 “slight risk” stretches farther out to include areas right 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 for all of these areas will be damaging winds, large hail and tornadoes.
The “enhanced risk” area has the greatest probability of strong EF2-EF5 tornadoes. An EF2 tornado has winds of at least 111 mph or higher, and an EF5 tornado has winds that exceed 200 mph.
Forecasters are also concerned the storms are projected to hit overnight.
“Severe thunderstorms capable of producing several tornadoes and scattered to numerous damaging winds appear probable from mainly Friday evening into Friday night across parts of the lower/mid Mississippi Valley into the lower Ohio Valley and Tennessee Valley,” the SPC says. “Some of these nocturnal tornadoes may be strong.”
When tornadoes occur during the day, people are awake, alert and make a conscious effort to seek out weather alerts. At night, when everyone is sleeping, that is a different story.
Nocturnal tornadoes are more fatal
Texas on average has 140 tornadoes every year, the most of any state. Kansas, Florida, Oklahoma, and Nebraska round out the top five.
But the total number of tornadoes does not always tell the whole story. For example, despite Alabama having on average 42 tornadoes per year – more than three times fewer than Texas – it is at the top of the list for tornado fatalities.
Alabama averages 14 tornado fatalities per year, almost double the next highest, Missouri’s eight deaths per year.
Southern states such as Tennessee, Kentucky and Arkansas also see more tornadoes overnight than any other states. This can lead to higher fatalities, since many people are sleeping and unaware that 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 a number of reasons for this, some weather and some geographic. Southeastern tornadoes often travel faster, moved by a faster jet stream.”
On Friday, the severe storms are expected to push through many of those Southern states that are prone to nocturnal tornadoes, making warning or alerting systems all the more essential.
“Friday night is a time window that everyone needs to watch closely, have multiple ways to receive weather alerts, and know exactly what your plan of action is in case severe weather threatens,” the National Weather Service office in Paducah, Kentucky, said Thursday.
Whether you’re using a weather radio, an app on your phone or any other alerting system, make sure the devices are charged and ready to go for Friday.
CNN meteorologists Judson Jones and Monica Garrett contributed to this story