Photo by Chip Somodevilla/Getty Images

A monster storm was bearing down on the middle of the United States on Tuesday, with freezing rain and sleet pelting several states from Texas through Ohio ahead of blizzard conditions expected overnight.

Parts of nine states — Oklahoma, Kansas, Missouri, Iowa, Illinois, Indiana, Wisconsin, Michigan and Ohio — were covered by a blizzard warning Tuesday morning, TODAY's Al Roker reported.

Chicago could be among the worst hit areas, with blizzard conditions possibly starting Tuesday evening and up to 2 feet of snow in some areas of the city by Wednesday morning.

Early indications were ominous. Parts of southwest Missouri already had 6 inches of snow by 8 a.m. About 3,000 were without power in Ohio, 2,600 in Oklahoma. Roads were ice-covered and virtually impassable in several states.

The storm cut a 2,100-mile swathe across the country and has the potential to impact about 100 million people, or one-third of the U.S. population, according to The Weather Channel.

The National Weather Service's national map of advisories and warnings was a patchwork of different color-coded alerts, showing a country under siege by the storm.

As the storm began its trek, it brought a bit of everything: ice, sleet and snow — even tornadoes in the South were possible. School districts, universities and legislatures closed; airlines canceled nearly 5,900 flights; and residents rushed to gather supplies, anticipating they might have to dig out or hunker down.

 Forecasters predicted a hodge-podge of brutal winter weather — 24 inches of snow in some places, up to an inch of ice plus snow in others. Making matters far worse was the expectation of shivering cold and winds gusting to near 60 mph.

"What really gives us nightmares is the prospect of widespread power outages," said Jeff Rainford, chief of staff for St. Louis Mayor Francis Slay. "It's cross-our-fingers time."

When the snow finally ends, bitter cold will set in. Temperatures in some parts of the Midwest will dip well below zero. Gusty winds will blow all of that snow. Visibility will be virtually zero at times.

The system was also expected to cause disruption in the Northeast; more than 200 schools were closed in Pennsylvania, NBC News reported, and similar announcements were expected from the New York tri-state area and up through New England.