A sprawling winter storm hit the US with strong thunderstorms and tornado warnings that brought cities across the Midwest to a standstill with more than half a foot of snow.

The violent storm with 55mph (88 kph) winds and hail moved through the Florida Panhandle and into parts of Alabama and Georgia by sunrise on Tuesday, along with at least several reports of radar-confirmed tornadoes, the US National Weather Service said.

A wind gust of 106mph (171 kph) was recorded before dawn near the coast in Walton County, Florida.

“We still have potentially strong storms in that area through (Tuesday) morning and the potential for more severe weather and tornadoes,” meteorologist Lance Franck in Tallahassee said.

Winter Weather Nebraska
Snow coats a cow in Palmer, Nebraska (Josh Salmon/The Independent via AP)

A section of Panama City Beach, Florida, showed parts of roofs blown away, furniture, fences and debris strewn about and a house that appeared tilted on side, leaning on another home, WJHG-TV reported.

In Panama City, about 10 miles (16km) away, police early on Tuesday asked residents to stay indoors and off the roads “unless absolutely necessary” as officers checked on damage from the storms, including downed power lines and trees.

Florida Governor Ron DeSantis activated the Florida State Guard on Monday night to prepare for any storm-related impacts.

A number of schools were closed in the region and more than 140,000 customers were without power in Florida, Alabama and Georgia, according to the PowerOutage.us website.

In the Midwest, where a snowstorm started on Monday, up to 30cm of snow could blanket a broad area stretching from southeastern Colorado all the way to the Upper Peninsula of Michigan, including western Kansas, eastern Nebraska, large parts of Iowa, northern Missouri and northwestern Illinois, said Bob Oravec, a forecaster with the National Weather Service in College Park, Maryland.

From there, the storm was expected to head east, bringing a combination of snow, rain and strong winds to the North East by Tuesday night, as well as concerns about flooding in areas such as New England, parts of which got more than a foot of snow on Sunday.

Whiteout conditions in central Nebraska and Kansas closed long stretches of motorways.

In Nebraska, federal courts in Omaha and Lincoln closed on Monday, and the US Army Corps of Engineers increased the water flow at a Missouri River dam on the Nebraska-South Dakota border near Yankton to reduce the chance of ice jams forming. Dubuque, on Iowa’s eastern border with Illinois, closed its city offices on Tuesday. Schools in Cedar Rapids in eastern Iowa were among those also closing.

The weather has already affected campaigning for Iowa’s January 15 precinct caucuses, where the snow is expected to be followed by frigid temperatures that could drift below zero degrees (minus 18C).

It forced former US president Donald Trump’s campaign to cancel multiple appearances by Arkansas Governor Sarah Sanders and her father, former Arkansas Governor Mike Huckabee, who had been scheduled to court Iowa voters on Mr Trump’s behalf on Monday.

Madison, Wisconsin, was under a winter storm warning until early Wednesday, with as much as 23cm of snow and 40mph (64 kph) winds.

Northwestern Illinois was also under a winter storm warning with forecasts predicting 18 to 30cm of snow by early Wednesday.

The Chicago area as well as Gary, Indiana, were under winter storm advisories, with forecasts predicting 15cm of snow.

Disruptions extended as far south as the Oklahoma panhandle, where Cimmaron County emergency managers asked people to stay at home.

Another storm was on the way that will affect the Pacific Northwest into the northern Rockies, forecasters said. Blizzard warnings were out for much of the Cascade and Olympic ranges in Washington and Oregon.