The latest go-round of bad weather began overnight in some places - just in time to delay tens of thousands of deliveries of Valentine's Day flowers - as snow, sleet and rain fell on roads already covered in many parts of the Northeast with deep puddles and icy patches.
By the time it stopped in Pennsylvania, 22.5 inches of snow was reported in Somerset County, 20 inches in Berks and York counties, and almost 19 inches in Allentown, according to the National Weather Service. Parts of upstate New York got between 12 and 27 inches of snow.
The sloppy mix of snow and face-stinging sleet grounded more than 6,500 flights nationwide on Thursday and closed schools, businesses and government centers. About 1.2 million utility customers lost power as the storm moved from the South through the Northeast, dropping to about 440,000 outages by Friday morning, mostly in South Carolina and Georgia.
"Every time it snows, it's like, "Oh, not again,'" said Randal DeIvernois of New Cumberland, Pa., which had about 10 inches of snow by midafternoon Thursday. "I didn't get this much snow when I lived in Colorado."
By Friday morning, the number of flight cancellations dropped to about 1,110 nationwide. Many schools remained closed in Connecticut, Maine, Massachusetts, New Hampshire, New York state, Pennsylvania, Vermont and Virginia, while some in Rhode Island were opening late.
The treacherous weather was blamed for nearly two dozen deaths, many of them in motor vehicle accidents.
In New York, 36-year-old Min Lin died after she was struck by a utility vehicle with a snowplow attached to it as it backed up outside a shopping center in Brooklyn. She was rushed by paramedics to a medical center, where her nearly full term, 6-pound, 6-ounce baby was delivered via cesarean section, hospital spokeswoman Eileen Tynion said.
The baby was in critical condition in the neonatal intensive care unit, she said.
No immediate charges were brought against the snowplow operator.
The snow, sleet and ice that bombarded the Southeast on Wednesday brought its ferocity into the Northeast a day later.
Washington, D.C., received 9 inches of snow Thursday, Westminster, Md., reported 19 inches, and Newark, Del., had 14 inches.
Philadelphia had 11 inches, its fourth 6-inch snowstorm of the season - the first time that has happened in the city since record-keeping began in the late 1800s. New York City received nearly 10 inches, and parts of New Jersey had more than 11.
In New York City, the teachers union and TV weatherman Al Roker harshly criticized Mayor Bill de Blasio's decision Thursday to keep schools open. Roker, who was in Russia for the Winter Olympics but has a daughter in New York's public schools, said on Twitter: "It's going to take some kid or kids getting hurt before this goofball policy gets changed."
He largely stood by his criticism on Friday but apologized on NBC's "Today" show for a tweet forecasting "one term" for de Blasio, saying that was "below the line."
The mayor said many parents depend on schools to watch over their children while they are at work and keeping the schools open was the right decision.
Across the South, the storm left in its wake a world of ice-encrusted trees and driveways and snapped branches and power lines.
In South Carolina, about 242,000 homes and businesses were without power Friday morning, and officials warned it could be next week before it is restored for everyone.
The worst damage was in rural areas outside of Columbia and Charleston, mostly served by smaller utilities under The Electric Cooperatives of South Carolina.
"Some of our co-ops have never seen the damage on this scale before. For them, this has been a storm of historic proportions," said Todd Carter, vice president of loss control and training for the organization.
Gov. Nikki Haley planned to visit Aiken and Walterboro on Friday to look at some of the most heavily damaged areas.
In North Carolina, where the storm caused huge traffic jams in the Raleigh area on Wednesday as people left work and rushed to get home in the middle of the day, National Guardsmen in high-riding Humvees patrolled the snowy roads on Thursday, looking for any stranded motorists.
Around the country, this is shaping up as one of the snowiest winters on record. As of early this month, Washington, Detroit, Boston, Chicago, New York and St. Louis had gotten roughly two or three times as much snow as they normally receive at this point in the season.
The procession of storms and cold blasts - blamed in part on a kink in the jet stream, the high-altitude air currents that dictate weather - has cut into retail sales across the U.S., the Commerce Department reported Thursday. Sales dipped 0.4 percent in January.
This latest round of bad weather threatens to disrupt Friday's deliveries of flowers for Valentine's Day.
"It's a godawful thing," said Mike Flood, owner of Falls Church Florist in Virginia. "We're going to lose money. There's no doubt about it."
Ronald Reagan Washington National Airport was virtually silent Thursday, with all flights canceled. Travelers tried to catch some sleep in the terminals.
Rob Wolcott, of Washington, and his wife were trying to reach the Caribbean island of St. Kitts, where he was planning to officiate at a friend's wedding on Saturday.
The future bride and groom are "a little stressed," Wolcott said. "But they'll figure something out. They will still get married, whether or not I am the one to do the actual officiating."
Scolforo reported from Lemoyne, Pa. Associated Press writers Kevin Begos in Pittsburgh; Michael Rubinkam in Berks County, Pa.; Kathy Matheson in Philadelphia; Sarah Brumfield and Brett Zongker in Washington; Matthew Barakat in Falls Church, Va.; David Dishneau in Frederick, Md.; and Jeffrey Collins in Columbia, S.C., contributed to this report.