Yet another big storm hit the snow-weary eastern and central United States overnight Monday, piling more white stuff on people enduring a merciless winter.

As many as 50 million people were in the path of the glacial weather, which will see temperatures far more frigid than normal, the National Weather Service warned, adding that the misery was forecast to last through much of the week for the eastern US.

"Incredibly, another arctic front will arrive to the East Coast by Wednesday night, and this will bring some truly frigid conditions with it," it said. "

"Some places from the Carolinas to the Mid-Atlantic may see some of the coldest weather since the mid-1990s! Numerous record low temperatures are expected."

Southern states not used to such cold weather were also hit.

The storm followed a track from eastern Kansas through Tennessee and West Virginia to the mid-Atlantic Coast, the New York Times said.

Most of the affected areas can expect a snowstorm about once a year. But states like Kentucky were seeing snowfall well above average, said Jim Hayes, a meteorologist at the weather service's Weather Prediction Center in Maryland.

"This is going to be a big event for them," he said. "They don't get that much snowfall very often," he said, according to the Times.

The Massachusetts Bay Transportation Authority said that after a series of mammoth storms in recent weeks it could take up to a month to restore the ageing system to full operation, if no more storms blow in. Boston braced for one to six inches more of snow, forecasters said, according to the Boston Globe.

- No end in sight -

Snowfall amounts of six to 12 inches (15 centimeters to 30 centimeters) were anticipated in much of the mid-Atlantic, which includes Washington DC as well as New York City some 200 miles (350 kilometers) to the north.

US forecasters said the storm will buffet a wide swath of the eastern United States with snow, gale-force winds and brutal cold.

Among the cities expected to be hardest hit by the temperature plunge are Erie, Pennsylvania, where thermometers are expected to fall to minus 28 degrees Celsius (minus 18.4 Fahrenheit) and Cleveland, Ohio, with minus 22 degrees Celsius (minus 7.6 degrees Fahrenheit).

The Flightaware air travel website said that some 1,500 flights had been cancelled by midday Monday, before the latest bout of inclement weather had been felt.

February has set a record as the snowiest month ever in Boston, with 10 times the snowfall it would get in a typical winter.

With the snowstorm expected to at least brush New England's most populous city, mountains of snow piling up were likely to grow even higher.

"No end appears in sight as to the brutal winter we have experienced," the NWS wrote in its Boston forecast.

Photos of the blanketed city showed snowplows clearing roads and tow trucks rescuing buried vehicles, while officials warned drivers to stay off the roads.