|Traffic moves on I-80 as the wind picks up and snow begins to fall in Iowa [GALLO/GETTY]
The central United States was caught in the grip of a historic winter storm on Wednesday, buried by drifting snow and sleet that closed major highways and grounded thousands of flights.
The storm - one of the largest winter storms since the 1950s, according to NASA - stretched for more than 3,000 kilometers (2,000 miles) from Texas to the northeastern state of Maine, and forecasters warned trying to get around could be deadly.
"Do not travel!," the National Weather Service warned.
Blizzard, winter storm and freezing rain warnings were issued for more than half of the 50 US states, and thunderstorms and driving rain drenched the warmer, southern end of the storm in Louisiana and Mississippi.
Officials warned the public to stay at home rather than try to brave the crippling and potentially record-breaking storm.
"Travel will be dangerous and life-threatening due to dramatically reduced visibilities and bitter cold wind chills," the National Weather Service warned.
High winds and freezing rain turned roads into deadly ice rinks and knocked down trees and power lines. By late Tuesday more than 60,000 customers had lost power in Indiana alone, in addition to 22,000 in Ohio, local media said.
States of emergency
Forecasts warned of dangerously cold temperatures, blinding snow and massive drifts as high as six to eight feet (1.8 to 2.4 meters.)
"Lurking behind this impressive winter storm is a powerful shot of Arctic air as a frigid surface high drops down from central Canada," the weather service warned.
Bismark, North Dakota was an icy -28 degrees Celsius at 0730 GMT, with wind that could cause frost bite on exposed skin in less than five minutes.
Wind chills were forecast to drop to 30 to 50 below in Colorado, Wyoming, Utah, the Dakotas, Kansas, Iowa, Nebraska, Minnesota and even parts of Texas.
States of emergency were declared in Illinois, Indiana, Missouri and Oklahoma and the National Guard was called out to help rescue stranded motorists.
Emergency warming shelters were also set up for people whose homes lost power.
Thousands of schools and government offices were closed and many businesses shuttered.
Snow had already piled up to as high as 20 inches (51 centimeters) in Oklahoma by 0300 GMT and was falling fast and hard in parts of Texas, Wisconsin, Minnesota, Missouri and Kansas.
FlightAware reported that airlines grounded more than 6,700 flights on Tuesday - about 20 percent of US commercial flights.
The top U.S. airlines United Continental, Delta Air Lines and American Airlines canceled more than 4,000 flights ahead of the storm.
Dallas-Fort Worth International Airport, a major hub, was closed briefly on Tuesday morning due to the ice storm and delays were averaging about three hours once it reopened.
Most of the airlines at Chicago's O'Hare airport - one of the busiest in the world - stopped operating after the blizzard set in Tuesday afternoon and said they "will have limited or no operations" Wednesday, the airport said.
Traffic was slowed on highways in and around New York City, and speed restrictions were imposed on the George Washington Bridge and the Tappan Zee Bridge, both of which span the Hudson River, due to the weather conditions, authorities said.
Missouri and Oklahoma were among several states that declared a state of emergency even before the storm hit.
"Everyone should stay inside today and not drive," Missouri Governor Jay Nixon said on local television.
In Tulsa, Oklahoma, conditions are so bad that the Tulsa World newspaper will not publish for the first time in its history, said publisher Robert E. Lorton III. Many subscribers couldn't find their Tuesday editions under the snow.
Chicago was expected to be among the hardest hit with up to two feet (60 centimeters) of snow and officials warned plows would not be able keep the streets clear.
In New York, officials preemptively banned tandem-trucks of all sizes from a major interstate. New York City residents were urged to use mass transit and to clear snow and ice from fire hydrants.
Illinois State police said much of the state's highway system was snow covered with large stretches "impassible."
In Missouri, where at least one woman was reported killed after losing control of her car, the state closed Interstate 70, a major highway, from one end of the state to the other and city of Tulsa, Oklahoma, was reported at a near standstill after a record 14 inches (35.5 centimeters) of snowfall.
Crop damage feared
The storm is expected to wreak havoc on agricultural operations in the Plains states, threatening the dormant winter wheat crop, cattle herds and grain deliveries.
Grain elevators across the southern Plains were working with limited shifts and icing on Midwest rivers was expected to slow loading of grain barges headed to U.S. Gulf export markets.
Meat processor Cargill Inc said it will reduce production at two U.S. Midwest pork plants ahead of the storm. Chicago soybean futures rose more than 1 percent early on Tuesday, hitting their highest level since July 2008 as the frigid winter storm boosted feed demand.
Freezing temperatures were proving dangerous for Oklahoma's 5.1 million head of cattle, its Department of Agricultural Food and Forestry said. "Hypothermia and dehydration are the two things we worry about," said spokesman Jack Carson.
The storm is unlikely to hurt first-quarter U.S. economic growth, but is another problem for state and local governments already beset by budget problems, Moody's Analytics Chief Economist Mark Zandi told Reuters Insider.
Many cities and towns have already drained their snow removal budgets for the year after a series of storms in January. February has started with no respite at all.