(Reuters) - A lethal blizzard paralyzed Buffalo, New York, on Christmas Day, trapping motorists and rescue workers in their vehicles, leaving thousands of homes without power and raising the death toll from storms that have chilled much of the United States for days.

At least 30 people have died in U.S. weather-related incidents, according to an NBC News tally, since a deep freeze gripped most of the nation, coupled with snow, ice and howling winds from a sprawling storm that roared out of the Great Lakes region on Friday.

Much of the loss of life has centered in and around Buffalo at the edge of Lake Erie in western New York, as numbing cold and heavy "lake-effect" snow - the result of frigid air moving over warmer lake waters - persisted through the holiday weekend.

Erie County Executive Mark Poloncarz said the storm's confirmed death toll climbed to 13 on Sunday, up from three reported overnight in the Buffalo region. The latest victims included some found in cars and some in snow banks, Poloncarz said, adding that the death tally would likely rise further.

"This is not the Christmas any of us hoped for nor expected," Poloncarz said on Twitter on Sunday. "My deepest condolences to the families who have lost loved ones."

New York Governor Kathy Hochul called it an "epic, once-in-a-lifetime" weather disaster that ranked as the fiercest winter storm to hit the greater Buffalo area since a crippling 1977 blizzard that killed nearly 30 people.

"We have now surpassed the scale of that storm, in its intensity, the longevity, the ferocity of its winds," Hochul told an evening news conference, adding that the current storm would likely to go down in history as "the blizzard of '22."

The latest blizzard came nearly six weeks after a record-setting but shorter-lived lake-effect storm struck western New York.

Despite a ban on road travel imposed since Friday, hundreds of Erie County motorists were stranded in their vehicles over the weekend, with National Guard troops called in to help with rescues hindered by white-out conditions and drifting snow, Poloncarz said.

Many snow plows and other equipment sent on Saturday and Sunday became stuck in the snow, "and we had to send rescue missions to rescue the rescuers," he told reporters.

The Buffalo police department posted an online plea to the public for assistance in search-and-recovery efforts, asking those who "have a snow mobile and are willing to help" to call a hotline for instructions.

The severity of the storm was notable even for a region accustomed to harsh winter weather.

Christina Klaffka, 39, a North Buffalo resident, watched the shingles blow off her neighbor's home and listened to her windows rattle from "hurricane-like winds." She lost power along with her whole neighborhood on Saturday evening, and was still without electricity on Sunday morning.