As much as 12 inches of snow could fall on Tuesday across five states, with lesser amounts expected to be much more widespread.

Hazardous winter weather was expected through early Wednesday, according to forecasters. The storm had dropped a wintry mix of precipitation across the Midwest overnight.

Snow began falling in the city of Pittsburgh around 3 a.m. after a winter weather advisory was issued for all of western Pennsylvania along with parts of Ohio, West Virginia, and Maryland. Most of the area saw 2 to 4 inches, with Pittsburgh picking up 3.6 inches.

The storm is expected to bring accumulating snow and icy conditions from Kansas into New England, where winter storm warnings are in effect across the region.

As New Englanders know, storms are not always well forecast, with snowfall amounts sometimes over or under forecast and some starting earlier or later than expected.

Colorado's first big winter storm of the season is in full swing this Wednesday morning, delivering the heaviest snowfall just in time for the commute and causing slow, slick travel along the I-25 corridor and the foothills.

Oklahomans are bracing for another round of winter weather Thursday, as a storm system could bring snow and ice to the state.

Snow will start falling in the Denver area early Wednesday morning, stacking up multiple inches as it continues throughout the day, according to the National Weather Service.