The U.S. east coastal area was hit by an overnight major snowstorm on Saturday, leaving a large number of Americans stranded as they were going home or shopping for Christmas.

The snowstorm, which originated over the Gulf of Mexico, started falling on most east coastal states, including Washington, D.C., Maryland and Pennsylvania, on Friday evening and the flakes continue to pour down by Saturday morning.

A sightseeing bus passes in front of the Capitol Hill during a snowstorm blanketing the East Coast in Washington D.C., Dec. 19, 2009. Forecasts called for up to 50 centimetres of snow across the region, including Washington, Baltimore, Philadelphia and reaching up to New York. [Xinhua]

The accumulation of snow would be as deep as 30 to 60 centimeters through Saturday night, according to local weather forecasts.

The National Weather Service has issued a major winter storm warning for most snow-hit areas, from the Carolinas in the south to Rhode Island in the north, through early Sunday, and from noon (1700 GMT) on Saturday until 11:00 a.m. (1600 GMT) Sunday for New York City.

"A major winter storm will impact the region tonight (Friday) through Saturday night. A very strong low pressure center will track from the deep south northeast to the Carolina coast, and then up the east coast through Saturday night," the National Weather Service said in an advisory.

"Heavy snow will make travel conditions extremely hazardous if not impossible. All unnecessary travel should be avoided. If you must travel, use your headlights, drive at slower speeds, and allow extra time to reach your destination," it added.

Runners do jogging during a snowstorm blanketing the East Coast in Washington D.C., Dec. 19, 2009. Forecasts called for up to 50 centimetres of snow across the region, including Washington, Baltimore, Philadelphia and reaching up to New York. [Xinhua]

Hundreds of thousands of Americans were expected to travel by road and air at the last weekend before Christmas, but they have to look at the Plan B as many flights were canceled and roads closed.

Some airlines including Delta and Virgin have announced their decision to suspend flight operation in D.C. area on Saturday, while other airlines also advised passengers to check their flight schedules in advance.

So far, there have been more than 500 flights canceled in and around the capital, said a CNN report, adding that the two-day snow could set a new record since 1909.

The storm system was expected to blow a wind up to 56 kilometers per hour and trigger near-whiteout conditions that would put drivers in hardship.

In Virginia, the storm has caused several hundred motorists to be stranded in the western part of the state, and rescuers were trying to help them out with four-wheel drive vehicles and Humveesand provided them with food and water.

Local authorities in storm-hit states have also declared the state of emergency on Saturday morning as hundreds of snow-removing trucks and staff were deployed to clear roads and help prevent ice from sticking.

A spokeswoman from Amtrak, a major train operator in the United States, said that the company was putting more crews on duty to keep ice from forming on the overhead power lines as well as taking other preventive measures.

The Coast Guard sent an airplane to fly from North Carolina to New Jersey, advising boaters to stay in port if they don't have a necessary reason to be on the water.

Earlier this week, the storm had left flooded homes and stranded drivers when it swept the Gulf and south Florida areas.