A blast of wind-driven snow and plunging temperatures created headaches for travellers Tuesday across the Midwest with cancelled flights and cars and tractor-trailer rigs sliding off highways.
A blizzard warning was in effect until midnight for counties north of Indianapolis, and up to 30 centimetres of snow was possible across Indiana's midsection and parts of Illinois.
As the storm pushed eastward, the National Weather Service issued winter storm watches and warnings extending from Iowa and Missouri across the Ohio Valley into parts of New England. Snow was already starting to fall in the mid-Atlantic states.
Cold air dragged southward by the weather system dropped the temperature at Grand Forks, N.D., from -24 C at midnight to -29 Cat mid-morning. Temperatures as low as -26 C were possible in northern Illinois.
In Chicago, O'Hare International Airport cancelled more than 400 flights Tuesday, city aviation department spokeswoman Wendy Abrams said. Midway Airport cancelled about 100 flights.
Several flights also were scrapped at the Indianapolis International Airport, and about 20 per cent of the flights out of Cincinnati's main airport were cancelled because of poor conditions elsewhere, spokesmen said.
Schools were closed in several states.
Highways closed, limited traffic allowed
Nearly 25 centimetres of snow were reported in west-central Indiana's Fountain County as of 7 a.m. Officials declared a snow emergency, and roads were closed except for "extreme emergency traffic."
Ohio state officials said roads were wet or snow covered in every county, and southbound lanes of Interstate 75 were closed in the Dayton area because of jackknifed tractor-trailer rigs.
Northeast Ohio expected up to 25 cm of snow Tuesday, plus 25 cm more by Wednesday night, when temperatures were expected to plummet.
Along the southern edge of the snow belt, freezing rain was expected to coat roads, tree limbs and power lines with ice Tuesday.
In New York state, where communities on the eastern end of Lake Ontario have endured a week of heavy lake-effect snow, forecasters said the storm could produce 20 to 50 cm in some areas.