The weather system is forecast to affect an 1,800-mile (2,900 km) corridor of the United States from Colorado to the mid-Atlantic. It started as rain from Mexico and turned to snow as it met icy air. The storm hit Kansas and Missouri on Friday and continued pummeling those states on Saturday, as it extended into parts of Iowa, Illinois, Indiana and Ohio, said US Weather Prediction Center meteorologist Andrew Orrison. The storm is dumping its heaviest snowfall on areas west of St. Louis, where about a foot and a half of snow was recorded, with more still falling on Saturday, Mr Orrison said.
More than 1,200 motorists in Missouri were stranded and there were four deaths on the roads, the Missouri State Highway Patrol said in a tweet on Saturday.
It was not immediately clear if the fatalities were all weather-related and a representative for the Missouri Department of Public Safety could not immediately be reached for comment.
Dozens of flights were cancelled at St Louis Lambert International Airport, which described the onslaught of snow, in a message on Twitter, as one of its biggest single-day winter storms in years.
Snow is forecast for the Appalachian Mountains and the mid-Atlantic on Saturday evening and Sunday.
A massive snowstorm is heading towards the US capital, Washington DC (Image: US Weather Prediction Center)
