Forecasters expected the storm to be followed immediately by a blast of face-stinging cold that could break records in more than two dozen cities and bring wind chills as low as minus 40 degrees this weekend.
Blizzard warnings and states of emergency were in wide effect, and wind gusts hit more than 70 mph (113 kph) in places. In parts of New England, snow fell as fast as 3 inches per hour.
Four people were killed in North and South Carolina after their vehicles ran off snow-covered roads, authorities said. Another fatality was reported near Philadelphia when a car could not stop at the bottom of a steep, snow-covered hill and slammed into a commuter train. A passenger in the vehicle was killed. No one on the train was hurt.
In New Jersey, Orlando Igmat's car got stuck in a snowbank along the Garden State Parkway in Tinton Falls as he drove to work at Verizon. He waited a half hour for a tow truck to pull him out.
"I didn't expect it (the storm) was going to be a heavy one. That's why I went to work today. I'm going to stay in a hotel tonight," he said.
More than 100,000 homes and businesses lost power at some point Thursday. While many outages were restored by the day's end, officials from the mid-Atlantic to New England warned that those numbers might climb again as strong wind gusts and frigid temperatures continue through Saturday.
In New England, the powerful winds brought coastal flooding that reached historic levels in areas. The frigid waters overwhelmed fishing piers, streets and restaurants, and stranded people in homes and cars, prompting dozens of evacuations and rescues.
In Portland, Maine, the high tide nearly matched the 14.17-feet reported during the infamous Blizzard of 1978 that walloped the Northeast.
In Boston, icy harbor waters poured into downtown streets near popular tourist and business areas. The National Weather Service said the waters reached "within a few tenths of an inch" of record levels and local officials across coastal Massachusetts braced for further tidal surges.
"We saw the water going over the sea wall, which was really scary," said Boston resident Sonia Calderon. "I don't know what kind of damage that's going to cause, but it's a little scary just to think about it."
Mayor Marty Walsh said some of the areas hadn't seen flooding in 30 years. "If anyone wants to question global warming, just see where the flood zones are," the Democrat remarked.
Schools, businesses and ferry services in parts of the Canadian coast were also shut down. Nova Scotia Power said it had more than 1,000 people at the ready in its biggest-ever pre-storm mobilization of personnel and resources.
The flight-tracking site FlightAware reported more than 5,000 canceled flights across the United States. Those included more than two-thirds of flights in and out of New York City and Boston airports.
Rail service was affected too. Amtrak operated a modified schedule between New York and Boston. Northeast Regional Service between Washington, D.C., and Newport News/Norfolk, Virginia, was canceled.
Some people took the weather in stride.
Mark Schoenenberger, a 45-year-old NASA engineer who lives in Norfolk, Virginia, put on his cross country skis so he could make a half hour trip to the bagel shop for some breakfast for his family.
"It's like 'Yay, I get to go out," he said.
The only concern he seemed to have was telecommuting while his kids were home from school. But "it's just noise," he said.
Waiting just behind the storm was a wave of bracing cold.
The National Weather Service said record low temperatures were predicted for 28 major cities across the northeast by dawn Sunday.
Boston expected a low around minus 11 overnight Saturday into Sunday. Portland, Maine, and Burlington, Vermont, could see minus 16 and 19, respectively, the weather service said.
The massive storm began two days ago in the Gulf of Mexico and first struck the Florida Panhandle.
Some meteorologists described it as a "bomb cyclone," a term that comes from the process of bombogensis, when the barometric pressure drops steeply in a short period.
As the storm wound its way through the Deep South early Thursday, it brought plummeting temperatures that caused highways closures in South Carolina and water main breaks in Mississippi.
Mississippi's largest city, Jackson, was put under a precautionary boil-water notice and portable toilets were placed outside the state Capitol because some of the toilets would not flush.
In Florida, it was so cold iguanas fell from their tree perches in suburban Miami. The reptiles became immobile when temperatures dipped below 40 degrees Fahrenheit (5 degrees Celsius).
As the storm rumbled through New England Thursday afternoon, Marcus Slaga hunkered down at a hotel bar in Boston's partly flooded Seaport District. The 44-year-old sushi chef said his morning flight to Austin, Texas, was among the many canceled.
"I was hoping to wear shorts by this weekend," Slaga laughed. "Now, I'm stuck here for a couple of more days."
Collins and Susan Haigh reported from Connecticut. Associated Press writers Ben Finley in Norfolk, Virginia, Martha Waggoner in Raleigh, North Carolina, Michelle R. Smith in Providence, Rhode Island, Michael Casey, Rodrique Ngowi and Mark Pratt in Boston, Anthony Izaguirre in Philadelphia, Frank Eltman in Farmingdale, New York, and Julio Cortez in Tinton Falls, New Jersey, contributed to this report.
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