"Do not travel! Stay inside!" is the alert from the National Weather Service, regarding a "life-threatening storm" that's hitting the Midwest Tuesday before sweeping across to the East Coast. The "potentially historic and destructive" storm is expected to be the worst of this already unusually harsh winter, and one of the biggest in recent years. As experts warn of blizzards, ice storms and sleet, bitter cold and civilization-stalling amounts of snow, here's a look at the latest "snowpocalypse" 2011, by the numbers:

100 million
Estimated number of people who could be affected by the storm

Portion of U.S. population potentially affected by the storm

Number of states under blizzard warnings, as of Tuesday

Number of flights canceled nationwide, as of Monday afternoon

-50 degrees
Expected temperature, with wind chill, in Colorado, Wyoming, the Dakotas, and Kansas

2 feet
Amount of snow expected in some areas, including St. Louis, Milwaukee, and Kansas City

4 tons
Amount of ice-melt pellets Do it Best Hardware, near St. Louis, sold in four hours Monday

Number of National Guard troops mobilized in Missouri to deal with the storm

40 mph
Expected wind speeds in ice storm hitting Indiana

Number of Indianapolis residents without power as of Tuesday morning

20 inches
Predicted snowfall in Chicago

23 inches
Chicago's heaviest-ever snowstorm, in January 1967

The average number of years between storms of this size in Chicago

Number of plow trucks (and modified garbage trucks) Chicago has at the ready

60 mph
Predicted speed of wind gusts in the Windy City

5 inches
Predicted snowfall in central and Western Texas

Sources: Bloomberg Businessweek, NPR, Weather Channel, AP, CNN, Chicago Tribune, Indy 6 News, AFP, Time