Holiday blizzards wreak havoc in central United States
The storm is expected to cause widespread disruption
A "humongous" winter storm is rolling across the central US, bringing chaos to road and air transport from Texas to Minnesota.
Icy roads were blamed for the deaths of 14 people, mostly in Nebraska and Kansas. Some 100 flights leaving Minneapolis were cancelled.
The US weather service said the storm was spanning two-thirds of the country.
It advised against non-essential travel and scores of churches cancelled Christmas services.
I'd rather have people stay home than do their funerals in a couple of weeks
Rev Roger Claxton Grace Memorial Episcopal Church, Wabasha, Minnesota
Up to 2ft (60cm) of snow was possible in some areas by Christmas Day (Friday), forecasters said.
Scott Blair, a National Weather Service meteorologist in Topeka, Kansas, said the wind was becoming a serious issue in the central part of that state, with gusts reaching 40mph (64km/h).
"We're going to see blowing snow," he said. "The big concern comes later when we see snowfall with the wind, causing reduced visibility."
The US East Coast is still recovering from record snowfall last weekend, which brought much of the capital Washington DC to a standstill.
The new storm is expected to glaze highways in the east with ice over Christmas, the Associated Press reports.
Blizzard warnings were issued for Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma, South Dakota, Texas and Wisconsin, and drivers were encouraged to pack emergency kits before setting out during what is normally one of the busiest travel periods of the year.
By Stav Danaos, BBC Weather Centre
The storm system developed across western parts of the US, producing dust storms across the desert areas of California and Arizona.
The same system is now currently across the Midwest and is generating severe blizzards from Kansas to Minnesota.
As the system pushes eastwards, forecasters expect an ice storm to affect large parts of the interior of the north-east US during Christmas Day and Boxing Day.
"There's just a humongous storm moving across the centre of the country, basically from the Canadian border to Texas and spreading from west Colorado to Illinois," Pat Slattery, a spokesman for the National Weather Service, told AFP news agency.
"This is not a storm to be messed with."
He said freezing rain and high winds was making driving extremely dangerous.
"The wind is killer, especially when you're empty," trucker Jim Reed told AP during a stop in Omaha, Nebraska.
"Anything that's boxed, like a refrigerator trailer like I have, becomes like a giant sail in the wind."
More than 20 vehicles were involved in a pile-up on Interstate 40 in Midwest City, Oklahoma.
The Rev Joseph Mirowski of the Greek Orthodox Church of the Transfiguration in Mason City, Iowa, cancelled his Christmas Eve service as the area braced itself for up to 1ft of snow.
"I don't think God wants anyone to get killed or break a hip or break a knee or something," he said.
At the Grace Memorial Episcopal Church in Wabasha, Minnesota, the Rev Roger Claxton cancelled his Christmas Eve service out of fear his congregation's senior citizens would feel compelled to attend.
"I'd rather have people stay home than do their funerals in a couple of weeks," he remarked.
Texas Governor Rick Perry activated military personnel to help drivers while North Dakota Governor John Hoeven placed additional state troopers and the National Guard on standby.
The latest storm began in the south-west on Tuesday, causing blizzard-like conditions and travel chaos, before spreading to the east and north.
Flooding was predicted across Texas and into the Ohio Valley.
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