A major, disruptive winter storm was sweeping across the central U.S. on Sunday, forecasters said, bringing with it a dreaded combination of snow, ice and plunging temperatures.

The National Weather Service issued winter storm warnings from Kansas and Missouri — where blizzard conditions are expected — to New Jersey.

Even some parts of Alabama could see light snow Monday. At the end of the week, snow is possible across a larger portion of the state.

In Missouri and Kansas, where blizzard warnings were in effect, travel “could be very difficult to impossible,” with snow whipped around by high winds reducing visibility, the NWS said. Gusty winds could bring down tree branches.

“Do not travel unless necessary!” the NWS said.

The polar vortex of ultra-cold air usually stays penned up around the North Pole, spinning like a top. But sometimes it escapes or stretches down to the U.S., Europe or Asia — and that’s when large numbers of people experience intense doses of cold.

Studies show a fast-warming Arctic gets some of the blame for the increase in polar vortex stretching or wandering.

Snow and ice in the forecast

By Saturday evening, widespread heavy snow was likely between central Kansas and Indiana, especially along and north of Interstate 70.

The storm was forecast to move then into the Ohio Valley, with severe travel disruptions expected. It will reach the Mid-Atlantic states on Sunday into Monday, with a hard freeze even expected as far south as Florida.

Severe thunderstorms, with the possibility of tornadoes and hail, were also possible ahead of the storm system’s cold front as it crosses the Lower Mississippi Valley, the National Weather Service warned.

Parts of upstate New York saw 3 feet (0.9 meters) or more of snow from a lake effect event expected to last until late Sunday afternoon.

“Please stay off the roads. Crews are seeing too many vehicles out and sliding off,” Missouri’s transportation department said on the social platform X.

Air travel also was snarled

The Kansas City International Airport temporarily halted flight operations in the afternoon due to ice. Dozens of flights were delayed, including a charter jet transporting the Kansas City Chiefs, before the runways reopened.

“Work will continue overnight to keep the airfield clear,” Mayor Quinton Lucas said in a message on X.

Temperatures dip, though no records break

Starting Monday the eastern two-thirds of the country will experience dangerous, bone-chilling cold and wind chills, forecasters said. Temperatures could be 12 to 25 degrees (7 to 14 degrees Celsius) below normal as the polar vortex stretches down from the high Arctic.

In Chicago on Saturday, temperatures hovered in the teens (minus 7-10 Celsius) and around zero in Minneapolis (minus 18 C), while dropping to 14 below (minus 25 C) in International Falls, Minnesota, on the Canadian border.

Disruptions extend southward

Virginia Gov. Glenn Youngkin declared a state of emergency Friday evening ahead of the storm and encouraged residents to vote early on Saturday ahead of the state’s special elections Tuesday in a statement on X.

Alabama will see very cold temperatures extending throughout the week.

Similar declarations were issued in Kansas, Kentucky, Maryland and multiple cities in central Illinois.

“This is the real deal,” meteorologist John Gordon said at a press conference in Louisville, Kentucky. “Are the weather people blowing this out of proportion? No.”