The storm is expected to scatter heavy snow, sleet and freezing rain around the Deep South as a blast of Arctic air plunges much of the eastern U.S. into a deep freeze.

Nearly 2,000 flights within the U.S. or entering or leaving the country were canceled Tuesday with about 10,000 more flights delayed, according to online tracker FlightAware.com. In Texas, both Houston airports said that flight operations would be suspended starting Tuesday in expectation of hazardous conditions.

The East Coast endured a thick blanket of snow while people from the Northern Plains to the tip of Maine shivered in bitterly cold temperatures from the frigid arctic air mass that sent temperatures plunging well below normal. Dangerously cold wind chills were expected to persist through Tuesday morning.

Lakesha Reed, manager of Beaucoup Eats catering in New Orleans, had plans to fly out Tuesday to cook for a Mardi Gras-style event in the nation’s capital, but flights were canceled amid extreme cold. The 47-year-old New Orleans native said it was in the 30s early Monday afternoon in her port city, where near-freezing temperatures are rare.

“We can barely drive in the rain,” she said. “Last year, we wore shorts for Mardi Gras.”

Winter storm warnings extended from Texas to North Carolina on Tuesday, with heavy snow, sleet and freezing rain expected to move eastward through the region into Wednesday. Meanwhile, a state of emergency was declared Monday night across at least a dozen counties in New York as heavy lake-effect snow was expected around Lake Ontario and Lake Erie through Wednesday — with 1 to 2 feet (30 to 60 centimeters) possible — along with extreme cold temperatures.

Snow on the Gulf Coast

Ahead of the storm, governors in Georgia, Louisiana, Mississippi and Alabama, declared states of emergency and many school systems canceled classes Tuesday.

The blizzard warning in effect until midday Tuesday was the first issued by the office in Lake Charles, Louisiana, according to meteorologist Donald Jones. Strong winds with heavier snow bands were reducing visibility, and areas across the Gulf South that rarely see snow are expecting near-record or record snowfall, Jones said.

“The last time we saw snow of this magnitude was way back in 1960, and prior to that, the previous snowfall record that even stands to this day was way back in 1895,” Jones said. “By modern standards this is going to be a historic and very memorable storm for this part of the world.”

In Harahan, a suburb of New Orleans, as a rare snowstorm began to cover the roads, a Harahan police officer without gloves rubbed his hands to warm them, after responding to a church security alarm. Sleet changed to snow as the sun rose, with scarcely a car on the road.

Before snow and sleet began falling Monday night, Houston Mayor John Whitmire asked residents to stay off the roads.

“Get prepared to be in your house, in your residence, in your warming place for the next 48 hours,” he said noting that temperatures weren’t expected to get above freezing until Thursday. “So don’t let even clear skies on Wednesday and other days fool you. This is a serious arctic blast.”

Snowfall rates of 1 inch (2.5 centimeters) per hour or more were possible from eastern Texas to the western Florida panhandle and historic snowfall of 3 to 6 inches (8 to 15 centimeters) was forecast along the Interstate 10 corridor including Houston; New Orleans; Mobile, Alabama; and Pensacola, Florida, according to the National Weather Service. Heavy snow, sleet and freezing rain are expected across Georgia, northern Florida and the eastern Carolinas from Tuesday night into Wednesday.

Forecasters warned the subfreezing morning lows could threaten sensitive vegetation and exposed plumbing in areas unaccustomed to bitter cold.

Return of the Arctic blast

Much of the Eastern Seaboard is enduring some of the coldest temperatures this winter. Frigid temperatures persisted across the eastern two-thirds of the country with multiple record lows possible through midweek, especially across the Gulf Coast and portions of the Southeast, the weather service said. Normal temperatures were only expected to return slowly by the end of the week.

The cold weather prompted Donald Trump to take the oath as president Monday from inside the Capitol Rotunda, upending months of meticulous planning for an outdoor inauguration. The last time an inaugural ceremony was held indoors was Ronald Reagan’s in 1985.

Wind chills were expected to reach minus 30 degrees to minus 50 (minus 34 C to minus 46 C) at times across portions of the Dakotas and into the Upper Midwest, posing an extreme risk of hypothermia and frostbite. Subzero wind chills were forecast to continue from the central plains eastward through Wednesday night.

The extreme cold prompted school districts across the upper Midwest to close schools Tuesday, so students wouldn’t have to endure the severe wind chills. Some schools were still holding online classes.

The weather service issued cold weather advisories across the Great Lakes region.

Like earlier this month, this latest cold snap comes from a disruption in the polar vortex, the ring of cold air usually trapped about the North Pole.

In Texas, Jonathan LeBron, plumbing manager at Nick’s Plumbing & Air Conditioning in the Houston area, said the company began fielding calls Monday from homeowners worried about frozen pipes.

Houston’s low temperature Tuesday will be about 18 (minus 8 C), according to the weather service, or low enough for water to freeze in pipes, expand and then cause the pipes to burst. Several inches of snow were also possible.