A monster winter storm is stretching across huge swathes of the US, turning to snow as it crept north, and forecasters said the worst was yet to come.
The storm was expected to affect as much as a third of the US population, from severe thunderstorms in the southeast and ice-coated roads in Texas to blizzard conditions and up to 60cm of snow in Chicago. Several regions were experiencing bitter cold, including Denver.
"We're looking at heavy snow from the Rockies to New England," said Pat Slattery, National Weather Service spokesman. Once the snow lets up today, affected areas will remain stuck in a deep freeze through the end of the week, he added.
The Dallas-Fort Worth international airport closed for several hours yesterday just as thousands of football fans began arriving in the city for the Super Bowl game on Sunday.
Major US. airlines said they had cancelled more than 5,400 flights ahead of the storm. More than 1,200 of those flights were in and out of Chicago-area airports, major airline hubs.
One of the hardest-hit cities was Kansas City, where a municipal state of emergency was declared and snow ploughs were pulled from runways at the international airport in late afternoon due to blowing snow and low visibility.
Statewide emergencies were declared in Missouri, Oklahoma, Illinois and Wisconsin. White-out conditions were reported on Interstate 44 between Oklahoma and Missouri, closing part of that highway, as well as Interstate 70 in central Missouri.
"Everyone should stay inside today and not drive," Missouri Governor Jay Nixon said on local television.
Storm-related outages knocked out power to more than 100,000 homes and businesses in at least eight states, including Texas, Louisiana, Arkansas, Missouri, Kentucky, Indiana, Illinois and Ohio.
The storm was expected to wreak havoc on farm operations in the Plains states, threatening the dormant winter wheat crop, cattle herds, and grain deliveries.