Story highlights A slight risk of severe weather remains for some, forecasters say

Forecasters downgrade the threat for overnight hours

At least 12 storm-related deaths in Mississippi, official says

Tens of thousands remain without power after Mississippi, Alabama storms

Myra Hilliard heard it before she saw it: The roar of what she believes was a tornado forming in her Stedman, North Carolina, neighborhood on Tuesday.

Then she opened her front door to see it chew through the tree line across the street from her house.

"I grabbed my phone, and I ran and jumped in the bathtub," she told CNN.

It was a scenario that played out repeatedly across the South as people were urged to keep an eye on the weather, with forecasters warning of tornadoes, high winds and hail spawned by storms that have left at least 35 people dead since Sunday.

By Tuesday night, much of the fear of severe storms that could produce large tornado tracks in the eastern half of the United States, from Mississippi to New York, dissipated after the National Weather Service's Storm Prediction Center downgraded the threat.

Some storm risks remain, including the possibility of large hail, damaging winds and flash flooding in portions of the South and East Coast, forecasters said.

Mississippi and Alabama -- where tornadoes Monday caused widespread destruction and several deaths -- were again in the bull's-eye for the worst of the forecast on Tuesday evening.

A number of tornado warnings expired Tuesday night in North Carolina, where forecasters say the storm was barreling north. Authorities were assessing damage.

Photos: Photos: Storm system brings tornadoes, flooding Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Police officer Robert Jonah walks through floodwaters in the Manayunk neighborhood of Philadelphia on Thursday, May 1. A powerful storm system, including a series of tornadoes, has claimed at least three dozen lives in several states this week. Hide Caption 1 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – People look for items to salvage from a relative's tornado-ravaged home in Louisville, Mississippi, on Wednesday, April 30. Hide Caption 2 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – On Florida's Gulf Coast, torrential rains reduced some streets to rubble, gouged huge gashes in others and left stretches of others submerged. Here, vehicles rest at the bottom of a ravine after part of the Scenic Highway collapsed near Pensacola, Florida, on April 30. Hide Caption 3 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – A truck is stuck in the middle of a flooded street after heavy rains in Pensacola on April 30. Hide Caption 4 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Volunteers throw tornado debris on a burn pile in Vilonia, Arkansas, on April 30. Hide Caption 5 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Jerry Estes salvages food items April 30 from the kitchen of his home that was damaged by a tornado in Louisville. Hide Caption 6 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – A large tree smashes a car in Tupelo, Mississippi, on April 30. Hide Caption 7 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – A tornado-damaged home near Fayetteville, Tennessee, is seen on April 30. Hide Caption 8 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Faye Busby shows where a tornado ripped off part of her home's roof in Graysville, Alabama, on Tuesday, April 29. Hide Caption 9 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – A kitchen shelf stands in what remains of a home in Louisville on April 29. Hide Caption 10 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – People work to clear a tree off a shed after a storm in Smiths Station, Alabama, on April 29. Hide Caption 11 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Bobbi Leggon and Sudie Carter work to salvage items from a friend's home in Tupelo on April 29. Hide Caption 12 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Charles Milam takes a break while searching his destroyed home in Tupelo on April 29. Hide Caption 13 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Carnesha Bennett, right, cries on a friend's shoulder after touring what remains of her mother's child care center in Louisville on April 29. Hide Caption 14 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – The remains of a large truck rest amid debris in Vilonia on April 29. Hide Caption 15 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Kevin Barnes searches the remains of his home in Tupelo on April 29. Hide Caption 16 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Constance Lambert embraces her dog after finding it when she returned to her destroyed home in Tupelo on Monday, April 28. Hide Caption 17 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Residents walk along a Tupelo street on April 28. Hide Caption 18 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Workers assist a resident in Louisville on April 28. A nursing home and the Winston Medical Center, Louisville's major hospital, were among the buildings hit. Hide Caption 19 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Jimmy Sullinger watches lightning as a storm approaches the gas station where he works in Berry, Alabama, on April 28. Alabama Gov. Robert Bentley declared a state of emergency for all counties. Hide Caption 20 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Justin Shaw, left, helps Nick Conway erect a flagpole April 28 at his destroyed home in Vilonia. Hide Caption 21 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – John Smith reacts after seeing what's left of his auto repair shop in Mayflower, Arkansas, on April 28. Hide Caption 22 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Dust and debris fly as workers flip a fallen wall while searching destroyed homes in Vilonia on April 28. Arkansas Gov. Mike Beebe said the storm was one of the worst to hit the state in recent memory. Hide Caption 23 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – Residents of Baxter Springs, Kansas, view damage on April 28. A tornado estimated to be three blocks wide rumbled through Baxter Springs, said Cherokee County emergency manager Jason Allison. Hide Caption 24 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – People walk between destroyed houses on April 28 in Mayflower. Hide Caption 25 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – The remains of a home are seen in Baxter Springs on April 28. Sixty to 70 homes and at least 20 businesses there were reported destroyed, Allison said. Hide Caption 26 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – A tornado touches down in Baxter Springs on Sunday, April 27. Hide Caption 27 of 28 Photos: Photos: Storm system brings tornadoes, flooding Storm system brings tornadoes, flooding – A funnel cloud is seen near Baxter Springs on April 27. Hide Caption 28 of 28

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Tens of thousands were without power in the South, where suspected tornadoes tore through homes and businesses late Monday. At least 17 people were killed in Mississippi, Alabama and Tennessee on Monday. Those deaths are in addition to 18 others reported in Arkansas, Oklahoma and Iowa from storms Sunday.

Search and rescue efforts were still under way in Louisville, Mississippi, about 90 miles northeast of Jackson, where a tornado the day before flattened a day care center, said Robert Latham of the Mississippi Emergency Management Agency.

Mississippi Gov. Phil Bryant said the twisters inflicted "severe damage" in Louisville. Winston Medical Center, Louisville's major hospital, was also among the buildings hit.

"One of the confirmed deaths we received is the manager of that facility," he said, adding that search and rescue crews were still combing through the debris for possible victims. All the children have been accounted for, he said.

Meanwhile, the storm that walloped Mississippi and Alabama overnight was making its way through parts of Florida, Georgia and the Carolinas, according to the Storm Prediction Center.

'It hurts to look'

Monday's storms left a trail of damage through several Mississippi and Alabama communities.

Mississippi authorities confirmed 12 deaths. Three people died in Alabama and two in Tennessee, according to officials.

In Tupelo, birthplace of Elvis Presley, buildings near a major commercial district on the city's north side were "wiped away," Scott Morris, a reporter for the Northeast Mississippi Daily Journal, told CNN's "The Lead."

Numerous trees and power lines were down, and "quite a few buildings are destroyed up there," Morris said.

The storm destroyed Britney Butler's home in Tupelo, WMC-TV reported.

"It hurts to look, because I won't come home tonight," said Butler, who still managed to smile after discovering her dog had come out unscathed. "Oreo means the most to me."

As things got ugly, Matt Laubhan, the chief meteorologist at Tupelo television station WTVA , took charge. He ordered station staff to take cover before walking off the set himself.

"Basement. Now ... let's go," Laubhan said.

Two people died in Lincoln County, Tennessee, near the border with Alabama.

Part of an elementary school there was torn away, the building's roof was ripped off and the storm hurled a school bus into the school, CNN affiliate WSMV reported . The bus and school were empty at the time, the station said.

Alabama also hit hard

One of the three Alabama deaths was a 21-year-old University of Alabama student from Tupelo, according to the school.

Jon Servati was a member of the school's swimming and diving team, the school's athletic department said in a statement. He died from injuries suffered at an off-campus home, the school said.

The other two deaths came at a trailer park near Athens, about 22 miles west of Huntsville.

The storm reduced a complex of houses and duplex apartments in the town to rubble. Downed power lines and gas leaks made the area dangerous, CNN's Brian Todd reported from Athens.

Authorities in Limestone County, where Athens is located, asked people to stay off roads wherever possible Tuesday. Emergency crews need unimpeded access to roads, and extensive damage and downed power lines make travel hazardous, authorities said in the message transmitted by the National Weather Service.

In Jefferson County, Alabama -- site of the state's largest city, Birmingham -- a fire station was hit, as was a church. People were trapped for a time in the church, but no one was seriously injured, Horace Walker, a spokesman for county's emergency management agency, told "New Day."

About 90,000 homes and businesses were without electricity Tuesday afternoon, according to Brian Corbett of the Alabama Emergency Management Agency. About 10,000 customers remained without power around Jackson, Mississippi, Entergy Mississippi reported.

Act II

Monday's storms were Act II of a powerful weather system that brought punishing thunderstorms to the central United States. Suspected tornadoes spawned by those storms on Sunday killed 15 people in Arkansas, two in Iowa and one in Oklahoma, authorities in those states reported.

Sunday's hardest-hit area was Faulkner County, Arkansas, where a suspected tornado shattered homes, tossed tractor-trailers and killed 11 people in the towns of Vilonia and Mayflower, including one death newly reported by authorities on Tuesday. Two children were among the dead.