WASHINGTON, Jan. 11 (Xinhua) -- A winter storm is spreading snow along a 1,500-mile path from Denver to New York City and may affect more than 20 million people over the weekend, U.S. weather service said.

The storm will crank up on Friday and should last until at least late Sunday before it peters out, according to a USA Today report.

Main areas in the path of the storm include Kansas City, St. Louis, Indianapolis, Louisville, Cincinnati, Pittsburgh, Washington, D.C. and Baltimore, said the report, noting that St. Louis should see the most snow from the storm, with as much as 8 inches likely.

For many places, this will be a long-duration winter storm event that lasts more than 12 hours and perhaps as much as 48 hours, AccuWeather said.