04/10/2010 05:12 am ET | Updated May 25, 2011

Big Winter Storm Hits Chicago, Could Bring 14 Inches Of Snow

Up to 14 inches of snow could blanket the area by Wednesday, and more than 600 flights have already been canceled during what is expected to be a lengthy winter storm.

"The storm is going to be a little bit of an unusual snow storm because of the long duration that's expected," Gino Izzi, a meteorologist for the National Weather Service, told the Chicago Sun-Times.

Though the snow began to fall early Tuesday, Tuesday evening is expected to bring the worst of it. Izzi told the Sun-Times there is expected to be a period of six hours when Chicago will experience northeasterly winds, which are favorable to lake effect snow.

Also on Tuesday evening, winds of 15 to 25 miles per hour are expected--but could we could see winds of up to 40 miles per hour late Tuesday into early Wednesday. The increased wind speed will produce drifting and blowing snow that could cause a "whiteout" in outlying areas.

Streets and Sanitation Commissioner Thomas Byrne told the Chicago Tribune that motorists should expect serious traffic for the Tuesday evening and Wednesday morning rush--and that the city's snow plows will be stuck in traffic along with everyone else. The Tribune reports:

Byrne said the city will concentrate on vital areas -- schools, hospitals, police and fire stations -- and the main roads.

Byrne said plows won't be able to get to most of the side streets until after Wednesday morning's rush hour. "People have to understand that the side streets are going to fall behind in these conditions," he said.

"This storm is the worst we've seen this year," Byrne said.

The National Weather Service's Winter Storm Warning for the Chicagoland area and Northwest Indiana continues until 4 a.m. Wednesday.

WGN meteorologist Tom Skilling believes 14 inches of snow is possible by Wednesday morning.

At Midway Airport, Southwest Airlines has canceled all flights beginning at 10
a.m. Tuesday through 10 a.m. on Wednesday, according to the city Department of Aviation. At O'Hare, more than 600 flights have been canceled and all flights are reporting delays of 45 minutes or more.

Many schools in the area were closed Tuesday due to the heavy snowfall. For a full list of closed schools, go here.

The storm warning covers all of the areas in the north central part of the state, including Chicago and Cook, DuPage, Kane, Kendall, Lake, McHenry and Will counties.

For up to date weather information, visit the National Weather Service Web site.