WASHINGTON, March 6 (Reuters) - Washington and its suburbs face what could be their heaviest snowfall in two years on Wednesday, as a fierce storm 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 before hitting the U.S. capital, the National Weather Service said.
"It will be a wet, heavy, gloppy snow consistent with wallpaper paste," National Weather Service spokesman Chris Vaccaro said.
The weather service said the snowfall could be the heaviest in Washington for two years.
The Storm Prediction Center in Norman, Oklahoma forecast that the Washington area would get several inches of snow overnight, with four to six inches (10 to 15 cm) accumulating by the end of Wednesday.
In Chicago, where the National Weather Service issued a winter storm warning lasting up to midnight on Tuesday, wind-whipped snow disrupted Tuesday's morning commute.
More than six inches (15 cm) of snow fell at Chicago's O'Hare International Airport, causing 900 flight cancellations, according to the Chicago Department of Aviation.
Wisconsin's transportation department listed numerous roads as snow-covered or slippery from the storm across southwestern Wisconsin, but no road closures.
Slick roads contributed to numerous crashes and a slow commute across the border 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 Minneapolis-St Paul Twin Cities area reported nine inches (23 cm) of snow and driving conditions on highways throughout the Twin Cities were still listed as "difficult" hours after the storm passed through. (Reporting by Edith Honan in New York; Editing by David Brunnstrom)