ST. LOUIS — A massive winter snowstorm making its way across the Midwest and into the Mid-Atlantic region dumped more than a foot of snow in parts of Missouri and contributed to at least five deaths.

The storm moved into Kansas and Nebraska from the Rockies on Friday, then east into Missouri, Iowa, Illinois and Indiana, covering roads and making driving dangerous. Part of Interstate 44 near St. Louis was blocked for hours Saturday, and at one point the Missouri State Highway Patrol warned of traffic delays as long as eight hours.

The storm was expected to spread east into the Mid-Atlantic region, with between 3 and 6 inches of snow expected in the Washington area, including parts of northern and central Maryland, by Sunday. Forecasters said heavier snow and higher amounts could fall in mountain areas north of Interstate 64, such as Charlottesville and Staunton, Va.

Missouri had gotten the worst of the storm by Saturday, with the National Weather Service reporting more than a foot of snow Saturday morning in some places around St. Louis and Jefferson City, and more than 18 inches in Columbia.

At least five people were killed in crashes on slick roadways in Kansas and Missouri. They included a woman and her 14-year-old stepdaughter whose car slid into the path of a semitrailer in Clinton, about 80 miles southeast of Kansas City, on Friday, the Missouri State Highway Patrol said. Another woman died when her car slid on U.S. 24 in northern Missouri and was hit by an oncoming SUV.

In Kansas, a 62-year-old man died after his pickup truck skidded on the Kansas Turnpike and hit a concrete barrier, according to the patrol. Another crash involving two semitrailers in snowy conditions killed a 41-year-old driver from Mexico, the patrol said. Missouri troopers responded to more than 3,000 calls for help through early Saturday afternoon.