Tens of thousands remained without electrical power Sunday as a result of the storms a day earlier. Officials in far-flung locations were assessing the damages while utility crews worked to restore power.
The storms toppled trees, ripped off roofs and, in some areas, reduced buildings to rubble. The National Weather Service confirmed a tornado with winds of around 130 mph (210 kph) hit a high school in Kershaw County, South Carolina on Saturday, causing extensive damage.
The National Weather Service said it was a tornado packing winds of at least 134 mph (215 kph) that hit Alabama's Pickens County on Saturday, killing three people.
"I could hear everything just coming apart," Larry Jones, standing amid the rubble in Pickens County, said in a video posted by The Tuscaloosa News.
Alabama Gov. Kay Ivey praised the state's first responders in a statement Sunday expressing grief over the deaths.
"This morning, I have reached out to both the county leadership as well as the legislative delegation to offer my deepest condolences in this terrible loss of life," Ivey's statement said.
In northwestern Louisiana, three fatalities were blamed on high winds. A man in his bed in Oil City, Louisiana, was crushed to death by a tree that fell on his home early Saturday. A couple in nearby Bossier Parish were killed when the storms demolished their mobile home. The National Weather Service said a tornado with 135 mph (215 kph) winds hit the area.
In Lubbock, Texas, two first responders were killed when they were hit by a vehicle at the scene of a traffic accident on icy roads; in Iowa, where a semitrailer on Interstate 80 overturned, a passenger was killed in similar road conditions.
Near Kiowa, Oklahoma, a man drowned after he was swept away by floodwaters, the Oklahoma Highway Patrol said.
In Wisconsin, high winds, towering waves and flooding caused millions of dollars in damage to Port Milwaukee on Lake Michigan. Port Director Adam Schlicht called it "an unprecedented event at Port Milwaukee."
Icy weather also complicated travel in some areas. Winter weather prompted the cancellation of more than 1,200 flights Saturday at Chicago's two main airports.
Schlicht said the port's international docks, which are closed for the season, sustained "significant damage."
High winds and icy weather were factors in power outages affecting tens of thousands of people in the South and the Northeast. The PowerOutage.US website, which tracks outages, reported more than 11,000 outages in New York as of Sunday evening. Outage numbers were falling but there remained more than 10,000 without power in West Virginia; roughly 17,000 in the Carolinas; 14,000 in Alabama; 20,000 in Mississippi, and 12,000 in Arkansas.
Entergy Corporation, said its subsidiaries serving Arkansas, Louisiana, Texas and Mississippi were working to restore power to roughly 30,000 Sunday, most in Mississippi and Arkansas. That was down from a peak of 134,000 outages in the entire Entergy system.
While most were expected to be restored later in the day, some in areas of Arkansas and Mississippi with extensive damage might take longer, said spokeswoman Lee Sabatini.
"They have had extensive infrastructure damage," Sabatini said of those two states.
For some, it was just the latest outbreak of extreme weather in months.
The storm system spawned a tornado Saturday near Tazewell, in northeast Tennessee, for the second time in less than three months. The National Weather Service said on Twitter that it appeared to have maximum winds of 65 mph (nearly 105 kph). No injuries were reported.
A tornado with 80 mph (about 130 kph) winds touched down in Tazewell on Oct. 31.