Dangerous overnight tornadoes and snow threatening millions on Friday night

‘Sprawling storm will impact more than half the country. It’s a classic clash of air masses,’ meteorologist says

Dangerous overnight tornadoes and snow are threatening to hit millions on Friday night and into the weekend.

The National Weather Prediction Centre said on Friday morning that “a major winter storm will expand across the Central Plains, Upper Midwest, and Great Lakes today and Saturday”.

They added that snow could fall at a rate of two inches an hour, which would lead to “near whiteout conditions and dangerous travel”. The centre said that in some areas, more than a foot of snow is expected.

More than 25m people between Texas and Ohio could be affected, CNN reported.

The Storm Prediction Centre said on Thursday that “severe thunderstorms Friday night into early Saturday morning” could cover the area from the Mississippi River “in eastern Arkansas and northern Mississippi northward into parts of the lower Ohio Valley”.

The risk for the area around Memphis, Tennessee is considered to be “enhanced”. A level three out of five risk has been issued for the area, which also includes Nashville, Tennessee, Evansville, Indiana, and areas of western Kentucky.

A “slight risk”, level two out of five, covers areas further out from the Mississippi River and the Ohio River Valley, including Little Rock, Arkansas, Jackson, Mississippi, Shreveport, Louisiana, and Louisville, Kentucky.

Harsh winds, hail, and tornadoes are the main threats to these areas. The areas covered by the “enhanced risk” could see winds between 110 and 200 miles an hour.

“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 [and] mid-Mississippi Valley into the lower Ohio Valley and Tennessee Valley,” the Storm Prediction Centre has said. “Some of these nocturnal tornadoes may be strong.”

States in the South, such as Tennessee, Kentucky, and Arkansas, experience more tornadoes at night, which tend to be deadlier as people are sleeping.

“Tornadoes in the Southeast tend to be more dangerous than their Great Plains counterparts,” meteorologist Brandon Miller said, according to CNN. “There are a number of reasons for this, some weather and some geographic. Southeastern tornadoes often travel faster, moved by a faster jet stream.”

The National Weather Service in Paducah, Kentucky said on Thursday that “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 winter storm moving across the central US has the ability to lead to heavy snow, strong winds, and large hail.

A large area could see six inches of snow. Southern Minnesota, Northern Wisconsin and parts of Michigan’s Upper Peninsula could see a foot of snowfall. The snow will come with strong winds, making for dangerous travel conditions.

Areas from the Central Plains to the Upper Great Lakes could experience slippery roads and bad visibility. The heavily used Interstate 90 could be one of the hardest-hit areas.

A High Wind Watch warning has been issued for large parts of Southern Michigan for much of Saturday. The National Weather Service has said that “widespread power outages are possible” as power lines can be taken down by the winds.

The strong winds could also affect areas in and around Lake Michigan, such as Chicago, with waves measuring between six and 13 feet (1.8 - 4m) being a possibility on the water.