Tornado outbreak live updates: 40 dead in cross-country storm system

A new tornado watch was issued Sunday for portions of West Virginia, Ohio and Pennsylvania.

The severe weather threat will be ramping up across this region over the next few hours, according to the National Weather Service.

The tornado watch is in effect until at least 4 p.m. ET. Funnel clouds could develop in Charleston, West Virginia, and Pittsburgh and Erie, Pennsylvania, the NWS said.

At least seven states from Florida to western Pennsylvania are under tornado watches.

"A couple tornadoes are also possible. Multiple lines and clusters of thunderstorms will continue to develop and sweep across the watch area through the afternoon hours," the NWS said.

Potentially damaging winds of up to 70 mph are expected in the severe weather areas, officials said. Slow-moving thunderstorms are also expected to impact several states with the possibility of flash flooding.

ABC News' Daniel Peck

At least 289,054 utility customers from Michigan to Georgia were without power Sunday morning, according to the website that tracks power outages nationwide.

Most of the power outages -- 235,654 -- were in Southern states, according to poweroutage.us. More than 54,000 power customers in North Carolina and more than 55,500 in Georgia were without electricity, according to the website.

Power outages were also being experienced in Tennessee, where nearly 27,000 customers were without power; Alabama, where more than 27,000 customers were without electricity; and Mississippi, where more than 10,000 customers were impacted.

More than 61,000 utility customers in Missouri and more than 14,000 in Ohio were without power, according to the power outage tracker. And in Michigan, nearly 40,000 customers were without electricity.

ABC News' Juwon Funes

A tornado watch was issued Sunday for southeast Georgia and the Carolinas, according to the National Weather Service Storm Prediction Center in Norman, Oklahoma.

Damaging winds up to 70 mph and a few tornadoes are possible from Sunday morning to early Sunday afternoon from Savannah, Georgia, and into Charleston and Columbia, South Carolina, and Wilmington, North Carolina, according to the NWS.

"A broken band of thunderstorms will continue east into the Watch area this morning within a weakly unstable airmass with very strong flow aloft," the NWS said. "A greater risk for wind damage along with a threat for a couple of tornadoes."

ABC News' Max Golembo

More than 250,000 customers were without power across six states early Sunday, according to Poweroutage.us, a site that tracks energy providers.

About 70,000 customers were without power in Georgia, followed by about 63,000 in Missouri. Another 42,000 were without power in Tennessee, followed by about 37,000 in North Carolina, about 36,000 in Alabama and about 10,000 in Mississippi.

Farther north, about 40,000 in Michigan and about 15,000 in Ohio were without power.

-ABC News’ Charlotte Slovin