By Ian Simpson
WASHINGTON (Reuters) - A major snowstorm could blanket much of the eastern United States late this week in the first wintry blast this season for tens of millions of people in the area, forecasters said on Tuesday.
The storm gathering strength over the eastern Pacific Ocean is expected to sweep across the United States and hit the eastern seaboard on Friday and Saturday, said Rich Otto, a National Weather Service meteorologist.
"Right now there's a lot of models that are pointing to this big snowstorm for a good portion of the eastern U.S.," said Otto, with the Weather Prediction Center in College Park, Maryland.
AccuWeather, a private forecaster, said areas from Charleston, West Virginia, to Boston could get heavy snow. More than 50 million people could be affected, it said.
Otto said that the system is expected to combine with colder air on the coast, creating conditions for a major storm.
Otto cautioned that the forecast could change. "It's way too early to be talking about amounts" of snowfall, he said.
For the Washington area, the Capital Weather Gang, a team of area meteorologists, forecast a 75 percent chance for 4 inches (10 cm) of snow, and a 15 percent chance for at least 20 inches (51 cm).
If it arrives, the system would be the first major snowstorm to hit the U.S. East Coast this winter. Temperatures in much of the region were unusually warm into December, with New Yorkers on the street in T-shirts and shorts at Christmas.[nL1N14C1UJ]
The storm warnings came as temperatures were well below normal for much of the Midwest and eastern United States, the National Weather Service said.
The Pacific storm is forecast to drop rain and snow on the western United States on Tuesday as it moves onshore, it said.
(Reporting by Ian Simpson)