Western New York state braced for a fresh wave of heavy snow on Wednesday after a freakish storm swept off the Great Lakes and deposited as much as five feet (1.5 meters), killing at least seven people and stranding motorists overnight.

The new bout of snow could bring three feet (1 meter) of snow in parts of Erie County, which includes the city of Buffalo.

"That's a year's worth of snow," said Deputy Erie County Executive Richard Tobe, noting a state of emergency remained in effect.

Driving was banned on many roads and 140 miles (225 km) of the New York State Thruway along Lake Erie and Lake Ontario were closed.

The storm inundated some areas, with snow falling at a rate of 5 inches (13 cm) per hour, while sprinkling only a few inches (cm) just a few miles (km) away, said National Weather Service meteorologist David Thomas.

The disparity is typical of the so-called lake effect, which occurs when cold air moves across the relatively warm Great Lakes, drawing in moisture and dropping snowfall onshore, Thomas said. The phenomenon can create intense squalls but leave nearby locations virtually unscathed.

In south Buffalo, snowmobiles were being used to respond to emergency medical calls and rescue stranded motorists while some 5,000 tons of snow was removed from the area, Buffalo Mayor Byron Brown said at a news conference.

New York Governor Andrew Cuomo declared a state of emergency for 10 counties, deploying National Guard troops to help residents.

To the west, ice on the Mississippi River from the cold blast forced the earliest winter closure of the shipping season on records which date back to 1969, the U.S. Army Corps of Engineers said.

At least seven deaths were attributed to the storm in the Northeast. Of those, the Erie County Sheriff's Department said a 46-year-old man was found in his car buried under about 15 feet (4.6 meters) of snow while another victim died in a traffic accident and three people died from heart problems.

Erie County Health Commissioner Gale Burstein said an elderly man with a cardiac condition died when he could not be transported to a facility that could provide the care he needed.

There were no details available about the seventh death.

A 23-year-old man in New Hampshire died in a traffic accident also tied to the storm, state police said.