Hundreds of flights were canceled and thousands delayed for travelers heading home after the Thanksgiving holiday as a deadly winter storm moved to the Northeast on Sunday, packing one last punch of snow and ice.
As the storm shifted east, flight delays and cancellations continued to pile up. As of 11:30 p.m., there were more than 1509 Sunday flights canceled in the U.S., compared with about 400 on Saturday, according to flight-tracking site FlightAware. Nearly 18,000 U.S. flights were delayed.
Airports with the most canceled flights included San Francisco International Airport with 82 and Newark Liberty International Airport in New Jersey with 63, according to FlightAware. Wind and rain caused some arriving flights at San Francisco to be delayed an average of 4.5 hours.
There were also dozens of flight delays in Chicago and Minneapolis.
The National Weather Service predicted more than a foot of snow in swaths of upstate New York and New England, as well as ice accumulations in parts of Pennsylvania.
In New York, numerous schools announced closings and Gov. Andrew Cuomo advised non-essential state employees to stay home as the storm was forecast to bring snow, sleet, wind and rain through the day Monday.
State police had responded to more than 550 storm-related crashes across New York by 7 p.m. Sunday and Cuomo placed National Guard personnel on standby. Icy roads caused numerous crashes on Interstate 84 in Pennsylvania on Sunday and a section of Interstate 81 north of Binghamton was closed because of icy conditions for a while.
The same storm has been pummeling the U.S. for days as it moved cross country, dumping heavy snow from parts of California to the northern Midwest and inundating other areas with rain.
It has been blamed for several deaths.
The bodies of a boy and a girl, both 5, were found in central Arizona after their vehicle was swept away Friday while crossing a swollen creek.
Also in South Dakota, a small-engine plane carrying 12 people crashed shortly after takeoff Saturday afternoon, killing nine people and injuring three others. Federal aviation investigators are looking into whether snowy weather was a factor.
Major highways reopened Sunday in Wyoming and Colorado, a day after blizzard conditions clogged roads with snow drifts.
Road crews were able to reopen all of Interstate 25 and most of I-80 in Wyoming early Sunday after strong winds abated. Major interstates in Colorado were also reopened.
Still, authorities warned travelers to remain alert for slick conditions and blowing snow.
The city of Duluth, Minnesota, was blanketed with 21.7 inches of snow as of 12 p.m. Sunday. City officials said streets were impassible and residents should stay inside.
Farther south, precipitation was in the form of rain and thunderstorms.
In the mountain communities northeast of Los Angeles, nearly 9,000 utility customers were without power because of the storm.
Another storm system developed in the mid-Atlantic Sunday and forecasters said it would move into a nor'easter through Monday.
The Associated Press contributed to this article.