Massive snowstorm stalks US northeast

A major US storm blowing in heavy snow and ice has left 800,000 homes and businesses without power.

A deadly winter storm has crept through the northeastern US spelling drudgery for millions and tragedy for a few, including an expectant mother killed by a snowplough.

US media counted some 16 to 18 people dead as a result of the storm, which has dumped a thick blanket of snow over the southern and eastern US states and on Thursday shut down federal government operations in Washington. The snow was up to 60cm deep in places.

One of the casualties was a 36-year-old pregnant woman, struck and killed by a snowplough in a New York parking lot. Her baby was delivered alive by caesarean section but remains in critical condition.

In Washington, a man from a local psychiatric hospital was found dead in the snow, Mayor Vincent Gray said.

The National Weather Service warned that the storm had edged its way up the battered east coast and was "bringing significant winter weather to the northeast".

"Heavy snow and gusty winds are expected in parts of the Appalachians and New England into Friday," it said, adding that the brutal weather system would then set its icy sights on the Canadian coastal region.

There was to be only a temporary respite for some after that, with forecasters predicting yet more snow and wintry weather for the US east coast on Saturday.

Delays and cancellations to flights are expected to last for several days as airlines scramble to clear a backlog.

Thousands of travellers were stranded on Thursday as major air hubs such as Atlanta and New York were closed down. Washington's Dulles International reported 35cm of snow.

Some 6500 flights were cancelled outright, and more than 3800 delayed, spelling misery for hundreds of thousands of passengers.

Nearly 800,000 homes and businesses lost power across 11 states along the eastern seaboard, with 340,000 outages in North and South Carolina, the Department of Energy said.

In Washington, buses were cancelled and city services struggled to keep even major roads open.

Schools were shut and the streets of the capital eerily deserted as federal workers stayed home or worked to scrape snow off footpaths and driveways that were quickly buried by the deluge.

Even the White House cancelled its daily news briefing, as skiers appeared nearby on the National Mall, the large esplanade at the centre of Washington.

New York, which saw the same abundance of snow, was under a weather advisory until 6am Friday, with 30cm of snow expected for the city.

Mayor Bill de Blasio warned New Yorkers that public transportation remained the best option for travel and that rubbish collection had been suspended.

Broadcasters fell over themselves to find superlatives to describe the "historic" and "mindboggling" "Snowmaggedon."

The storm is only the latest severe weather to hit the eastern United States in what was already the worst winter in 10 years.

But experts predicted it would have little long-term economic impact, perhaps knocking only about 0.1 per cent off first-quarter GDP growth, according to economic Doug Handler of IHS Global Insight.

Although the storm would mean a short-term drop in economic activity, consumers would spend more in heating fuel.