A strong storm system Friday will bring the potential for severe weather to 30 million people from the Lower Mississippi Valley to the lower Ohio Valley.

“A tornado outbreak (is) possible across portions of the Mid-Mississippi Valley Friday evening,” the Storm Prediction Center warned.

The storms will be capable of producing strong to intense (EF-3+) tornadoes, with long-track tornadoes possible.

The greatest risk of strong tornadoes includes more than six million people for places like Shreveport, Louisiana; Little Rock, Arkansas; Memphis, Tennessee; and Jackson, Mississippi.

“All those in the ArkLaTex would be advised to be prepared to receive warnings and have a shelter plan in place, with increased urgency directed towards locations with closer proximity to the Mississippi River Valley,” the weather service office in Shreveport warned.

While the most intense storms will occur during the evening hours, any storm through the day could launch a few weak tornadoes.

A tornado warning west of Dallas, lead to a ground stop at the Dallas Fort Worth International Airport early Friday morning.

Get the latest forecast for your area here

Damaging winds with gusts potentially over 75 mph and hail are expected through the day and into the overnight hours Friday.

Along with the tornado threat, there will be torrential rainfall that could lead to flash flooding.

Flash flooding threat for millions

The rain is expected across a large swath of the US stretching from Oklahoma to West Virginia.

Nearly 19 million people are under flood watches across at least eight states in the mid-South and central regions.

“A dangerous, flash-flooding and severe weather event is expected tomorrow (Friday), as heavy rainfall focuses along a slow-moving cold front across the Ohio Valley, while tornadoes, damaging winds, and hail develop south of the boundary in the Lower MS Valley and Mid-South,” the Weather Prediction Center warned Thursday afternoon.

The storm’s worst impacts were over the Oklahoma-Missouri border late Thursday, drenching parts of the states with 1 to 3 inches of rain in areas where a flash flood warnings is in effect. Those same areas can expect another 1 to 3 inches of rain overnight.

In addition to the heavy rain, large hail is also a primary threat along with damaging winds and the possibility of tornadoes.

Flood watches extend for more than 1,000 miles from Oklahoma and northern Arkansas eastward to southern Missouri, southern Illinois, southern and central Indiana, Ohio and West Virginia. A flood watch means conditions are favorable for possible flooding, and it’s not a strong indication flooding will occur, the National Weather Service explained.

The significant flood threat is expected to shift from northwestern Arkansas to western Ohio throughout the day Friday. Storm totals between 2 and 4 inches of rain are expected, with the heaviest rainfall potentially exceeding 5 inches in total.