NEW YORK — An arctic blast that gripped much of the United States on Saturday left more than 700,000 without power, at least 19 dead from weather-related car crashes and thousands stranded due to flight cancelations, Reuters reported.

Plummeting temperatures were expected to bring the coldest Christmas Eve on record, and energy systems across the country were strained by rising demand for heat and storm-related damage to transmission lines.

The latest outage numbers are a sharp drop from the 1.8 million US homes and businesses left without power as of early Saturday morning, according to tracking site Poweroutage.us.

Many electric companies continued to ask customers to conserve energy by not running large appliances and turning off unneeded lights.

Duke Energy by late Saturday afternoon told customers it had ended the 15-30-minute rolling blackouts across North and South Carolina that it had initiated earlier in the day until additional electricity was available.

Disruptions upended daily routines and holiday plans for millions of Americans during one of the year's busiest travel periods.

More than 2,700 US flights were canceled on Saturday, with total delays tallying more than 6,400, according to flight-tracking service FlightAware. More than 5,000 flights were canceled on Friday, FlightAware said.

The American Automobile Association had estimated that 112.7 million people would venture 50 miles (80 km) or more from home between Dec. 23 and Jan. 2. But stormy weather heading into the weekend likely ended up keeping many people at home.

Weather-related car accidents around the country left at least 19 dead and hundreds stranded on ice and snowbound roads, according to media reports.

The National Weather Service said its map of existing or impending meteorological hazards "depicts one of the greatest extents of winter weather warnings and advisories ever."

More than one million Americans and Canadians are facing Christmas Day without power as a massive winter storm continues to pummel North America.

A bomb cyclone, when atmospheric pressure plummets, has brought snow, strong winds and freezing temperatures.

Nearly 250 million are affected, and at least 19 deaths have been linked to the storm that extends more than 2,000 miles (3,200km) from Quebec to Texas.

The western US state of Montana is the worst hit by the cold, with temperatures dropping to -50F (-45C).

Near white-out conditions have been reported in Minnesota, Iowa, Wisconsin and Michigan. In the city of Buffalo, New York state, the US National Weather Service (NWS) reported "zero mile" visibility.

In the Pacific Northwest, some residents ice-skated on frozen streets in Seattle and Portland.

Coastal flooding has been seen in America's north-eastern New England region, inundating communities and downing power lines.

In Canada, a number of motorists have had to abandon their vehicles in blizzards in the province of Ontario

Even the usually milder southern states of Florida and Georgia are experiencing hard-freeze warnings.

The only region that has largely been spared the cold weather is California where continental mountain ranges are helping to protect the Golden State.

In Canada, the provinces of Ontario and Quebec were bearing the brunt of the Arctic blast.

Much of the rest of the country, from British Columbia to Newfoundland, was under extreme cold and winter storm warnings.

A number of the storm-related fatalities have involved road traffic accidents, including a 50-car pile-up in Ohio that killed four motorists. Another four died in separate crashes in the state.

Travel problems across the country were being exacerbated by a shortage of snowplow operators, with low pay rates being blamed.

The NWS says more than 100 daily cold temperature records could be tied or broken over the next few days. — Agencies