"Its effects run the gamut from severe thunderstorms in the Gulf Coast to ice in New England to really what is a raging blizzard in the lower plains," he added.
Parts of at least 10 central states, stretching from North Dakota to Oklahoma in the south, are now under blizzard warnings.
Jesse Swenson, sheriff's deputy for Guthrie County in Iowa, where six inches of snow fell, said: "Everybody wanted a white Christmas - and they got it."
Motorists took shelter in churches and high schools after traffic did not move for hours on icy highways.
About 200 passengers and staff were stuck at Oklahoma's largest airport on Thursday, as heavy snow forced the cancellation of 70 flights. The airport reopened on Friday morning.
In northern Oklahoma, the National Weather Service warned that "a band of very heavy snow along with isolated thunder... was producing up to four inches of snow per hour".
The capital, Oklahoma City was hit by 14in (35cm) of snow by Thursday night, eclipsing the record of 2.5in set in 1914.
The storm has dumped snow and ice across much of the US heartland
Winds of up to 50mph (80km/h) buffeted central Kansas, while gusts of up to 65mph in Texas left 5ft (1.5m) snow drifts in some areas.
The storm began in the south-west on Tuesday before spreading to the east and north.
The Midwest storm comes as the East Coast recovers from record snowfall last weekend, which brought much of the capital Washington DC to a standstill.
Forecasters warned of dangerous travel conditions in the eastern seaboard over the weekend, with freezing rain and heavy downpours expected from North Carolina to New England.
Flood warnings have been issued for parts of the north-east as the snow begins to melt.
Although severe, storms are not uncommon in the US during the winter months, says meteorologist Stav Danaos at the BBC Weather Centre.
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