Washington was due to be hit by heavy, wet snow on Wednesday as a fierce snowstorm headed east after blanketing the Midwestern United States, snarling traffic and causing hundreds of flight cancellations.

The storm was expected to move eastward over the Ohio Valley and then the central Appalachians and mid-Atlantic states on Wednesday, hitting Washington with its biggest snowfall in possibly two years, according to the National Weather Service.

"It will be a wet, heavy, gloppy snow consistent with wallpaper paste," said National Weather Service spokesman Chris Vaccaro.

The Washington area was expected to get several inches of snow overnight, with four to six inches (10 to 15 cm) accumulating by the end of the day on Wednesday, according to the Storm Prediction Center in Norman, Oklahoma.

In Chicago, where the National Weather Service issued a winter storm warning through midnight, residents girded for between 4 to 8 inches (10 to 20 cm) of snow.

During the evening rush hour, wind-whipped snow fell at a heavy rate throughout the Chicago area, according to the Illinois State Patrol, reducing visibility to less than half a mile and causing delays on roads.

Monique Bond, a spokeswoman with the state patrol, said bad weather may have been a contributing factor in a deadly crash on Interstate Highway 70 in Marshall, Illinois, near the Indiana border.

A female driver headed east on I-70 crossed the median and crashed into a westbound tanker trunk. The driver of the car and her young child died in the accident.

Most of the other weather-related incidents the state patrol responded to on Tuesday were spinouts involving single vehicles, Bond said.

More than six inches of snow fell at O'Hare International Airport, causing 900 flight cancellations, according to the Chicago Department of Aviation.

Southwest Airlines, which canceled nearly 250 flights out of Chicago's Midway Airport, resumed flight operations at 6 pm on Tuesday, the city aviation department said. But delays of an hour or more were common.

Wisconsin's transportation department listed numerous roads as snow-covered or slippery across southwestern Wisconsin, but no road closings.

Slick roads contributed to numerous crashes and a slow commute in Minnesota. The state's public safety department reported 215 crashes from 5 a.m. to 4 p.m. Tuesday, but no fatalities.

Several spots around the Twin Cities area reported nine inches of snow, and driving conditions on highways throughout the area were still listed as "difficult" hours after the storm passed through. - Reuters