After back-to-back days of severe thunderstorms and tornadoes in the Plains and South on Sunday and Monday, a third-straight day of dangerous weather is anticipated Tuesday.

Strong to severe thunderstorms were forecast from the Deep South to the Ohio Valley and Mid-Atlantic, affecting about 90 million people. Tuesday afternoon, severe-thunderstorm watches covered northern Mississippi, northern Georgia, and the Mid-Atlantic, while tornado watches stretched across the boot of Louisiana, central Mississippi and Alabama. Large hail, damaging wind and tornadoes are possible, especially in the zone from roughly Shreveport, La., to Birmingham, Ala.

By late afternoon, a damaging squall line had taken shape, spanning from north of Baton Rouge, La. to near Starkville in northeastern Mississippi. Winds gusting in the 60 to 70 mph range were common along the line of storms. The National Weather Service Storm Prediction Center highlighted the corridor along and south of Interstate 20 as having a Level 4 out of 5 severe-weather risk.

“Numerous to widespread damaging winds and a few tornadoes are expected through this evening across the Deep South,” the center wrote.

Occasional tornado warnings continued to appear where quick-forming circulations materialized along the line.

Additional lines of storms were marching through South Carolina and Virginia, packing strong winds. Washington D.C. found itself beneath a severe thunderstorm warning at 5 p.m..

In Alabama, training storms, or storms repeatedly passing over the same area, were causing flash flooding, including around Birmingham, where social media video showed streets resembling rivers:

Doppler radar estimated that as much as 5.5 inches of rain had fallen in the Irondale neighborhood of Birmingham by 4 p.m. Central Time, the swath of heaviest precipitation coming down just south of the city. Shuttlesworth Airport in Birmingham measured an inch of rain during both the noon and 1 p.m. hours.

Heavy rain continued to plague Alabama as downpours stalled along the warm front, and will increase in intensity before the cold front and squall line sweep through around 7 p.m.. That could bring another 2 to 4 inches of rain, with locally higher amounts, exacerbating the already ongoing flood threat.

The sprawling storm threat comes after nearly 400 reports of severe weather from Texas to Maryland on Monday. Tornadoes touched down in at least six states, with twisters tearing through the western suburbs of Atlanta and south of Dallas. The storms caused at least two fatalities in Georgia, according to Weather.com, while several injuries were reported in Texas.

The multiday onslaught of nasty storms began Sunday, when a tornado outbreak unleashed a string of twisters in Mississippi, where Yazoo City was hit hard, while a large wedge tornado prompted a dire “tornado emergency” as it sliced through Tupelo.

A threat of storms will continue Wednesday, shifting toward the southeast and Mid-Atlantic.

Tuesday’s severe weather threat

On Tuesday afternoon, national radar showed storms stretching from central Pennsylvania through the southern Appalachians and then curling westward through the South.

The Storm Prediction Center placed Birmingham, Jackson, Miss., and Alexandria, La. under a Level 3 out of 5 “enhanced” storm risk. A Level 4 risk was even drawn into southern Mississippi into southwest Alabama.

The Weather Service also declared an elevated risk of heavy rain and flash flooding, focused on the zone from southern Mississippi to northern Georgia. Amounts nearing 6 inches had fallen across northern Alabama, including along the Interstate 59/20 stretch.

The primary severe-weather hazard had transitioned to damaging winds and flooding as storms congealed into a squall line. A few isolated tornadoes can’t be ruled out, especially in the Deep South, as embedded bends or kinks in the squall line could yield brief spin-ups. A gust to 75 mph was clocked in Philadelphia, Miss.

Farther north through the Appalachians, the Carolinas, and Mid-Atlantic scattered strong to severe thunderstorms were ongoing. Numerous reports of severe weather were received from Virginia as storms marched east along a line from Richmond to the nation’s capital. A roof was blown off as structure in Daleville, along Interstate 81 north of Roanoke, with two mobile homes blown off their foundations in nearby Thaxton.

Between Charlottesville and Richmond, 50 trees were reportedly blown down in Carysbrook.

Wednesday’s storm threat

By Wednesday, storms won’t be packing as much of a punch, their territory confined to a narrowing strip along the Eastern Seaboard. A few thunderstorms will linger ahead of the cold front from the Florida Panhandle up the Interstate 95 corridor through the Carolina coastal plain and into the Mid-Atlantic.

Gusty winds are the primary concern.

Thereafter, the front clears the coast, bringing a few days of tranquil weather to the continental United States. The next chance of more widespread strong to severe thunderstorms will materialize on the Plains by later this weekend.

A recap of Monday’s damaging storms

Storms plowed east Monday, dropping a significant tornado just west of downtown Atlanta that rode as far east as the Perimeter Highway. It appears the tornado missed the heart of the city by just six miles. A partial apartment collapse was reported in Fulton along Riverside Drive and Fulton Industrial Boulevard, with numerous trees downed along the Kings Highway in Douglas.

A tornado warning was also issued for Charlotte, around midday. A tornado touched down in Clover, S.C., just 15 miles west-southeast of Charlotte Douglas International Airport. Video emerged of a farmhouse being heavily damaged. Tornado damage was also reported in Oakboro, about 30 miles east of the city.

By Monday afternoon, the atmosphere heated up once again, with more storms firing from the Plains to the East Coast. A tornado touched down east of Springfield, Ill., accompanying rotating or supercell storms that resembled towering flying saucers or “mother ships.”

Midafternoon, another tornado hit Northumberland, Va., and damaged homes near the Chesapeake Bay. One garage collapsed.

Monday evening, a classic “hook echo” appeared on radar in northeast West Virginia, associated with a supercell thunderstorm that churned from Berkeley County, W.Va., to north of Baltimore, dropping intermittent tornadoes. A structure collapse in Jefferson County, W.Va., resulted in one injury near Charles Town, while radar suggested another twister may have spun up in eastern Frederick County.

Later at night, storms dropped baseball-size hail in San Antonio, with five-inch stones reported west of the city. It comes less than a week after a trio of destructive hailstorms racked up billions in damage after hitting three major Plains metro areas. Other hailstorms plagued the Texas Hill Country and panhandle, dropping large hail and bringing winds gusting above 80 mph.

The immediate Dallas-Fort Worth metroplex missed the brunt of those storms — though suburbs to the south weren’t nearly as fortunate. A damaging tornado crossed Interstate 35E near Waxahachie, about 25 miles south of Dallas, flipping a semi tractor trailer and overturning several vehicles. Several people were hospitalized, according to the Weather Channel, and northbound lanes were shut down until 5:30 a.m. Tuesday. Mobile homes were obliterated or toppled.

Storm chaser Ian Osborne photographed the eerie cone tornado moments after it crossed the highway:

A confirmed tornado also caused damage on the northwest side of Fort Smith, Ark.