CHICAGO, Dec 20, 2012 (AFP) - The US Midwest's first major snowstorm of the winter caused "life-threatening conditions" and flight delays Thursday that could ripple into problems across the country as travelers gear up for the Christmas holiday.
A regional energy company said the storm had cut power to more than 40,000 households and businesses in Iowa, where nearly a foot (30 centimetres) of snow had fallen in the capital, Des Moines.
The Weather Channel said around 11 inches (27 centimetres) of snow covered parts of Wisconsin, with around eight inches (20 centimetres) in Omaha, Nebraska.
The storm dumped more than two feet of snow in parts of the western US, including Washington state and Wyoming.
Mass delays expected
Chicago's bustling O'Hare International Airport, one of the world's busiest, rated delays at five on a five-point index, hours before the snow was even expected to hit, in mid-afternoon, according to FlightStats.com.
The website reported Thursday morning that flights were being held up an average of just under two hours, and some flights slowed by up to four hours.
Flights through smaller airports in South Dakota and Iowa were cancelled Thursday morning.
The delays and cancellations could affect travel across the country, especially since many passengers need to change planes in Chicago -- and even if they do not, their aircraft may have to pass through there.
The national weather service forecast "intense snowfall rates," along with high winds and reduced visibility to start in Chicago by 3pm local time (2100 GMT).
Two major airlines, Delta and United, issued travel alerts allowing passengers to change their tickets without fees for travel through affected areas.
Further south, the weather service warned of a "life-threatening blizzard" that was located over central Missouri Thursday morning and heading into western Illinois by morning.
"This will result in life threatening conditions and nearly impossible travel overnight through today," the bulletin warned.
"Falling trees may also occur to due heavy snow accumulation on trees and high winds."
Many schools across Nebraska and Iowa were closed Thursday or opening late.
