The next round of bitter cold was expected to hit the southern United States on Tuesday after the first severe winter storm of the year inundated much of the country with ice, snow and wind.

The massive storm system caused disruption even in areas of the country that are normally spared from winter’s wrath. Trees fell in some southern states, a freeze threatened in Florida, and in Dallas people searched deep in their closets for hats and gloves.

Windy temperatures could drop to minus ten to minus 20 degrees Fahrenheit (as cold as -10.5 degrees Celsius) early Tuesday from Texas on the other side of the Gulf Coast, according to the National Weather Service. A low pressure area is then expected to form near South Texas as early as Wednesday, potentially bringing snow to parts of the state, including the Dallas area, as well as Oklahoma, Arkansas and Louisiana.

The polar vortex that dipped south over the weekend held icy grip on much of the country east of the Rocky Mountains on Monday, making many roads treacherous, forcing school closures and causing widespread power outages and flight cancellations.

Ice and snow covered major roads in Kansas, western Nebraska and parts of Indiana, where the National Guard was deployed to help stranded motorists. The National Weather Service issued winter storm warnings for Kansas and Missouri, where blizzards brought wind gusts of up to 45 miles per hour (72 km/h). The warnings extended into New Jersey into early Tuesday.

The polar vortex of ultra-cold air usually revolves around the North Pole, but sometimes plunges south into the United States, Europe and Asia. Studies show that a rapidly warming Arctic is partly responsible for the increasing frequency of the polar vortex, which is expanding its influence.

The eastern two-thirds of the U.S. struggled with bitter cold and wind chill on Monday, with temperatures well below normal in some areas.

A cold weather warning will go into effect along the Gulf Coast early Tuesday. In the Texas capital of Austin and surrounding cities, wind-chilled temperatures could drop as low as 15°F (-9.4°C).

Several cold days were expected in the northeast.

Hundreds of car crashes have been reported in Virginia, Indiana, Kansas and Kentucky, where a state trooper was treated for non-life-threatening injuries after his patrol car was struck.

Virginia State Police responded to at least 430 crashes on Sunday and Monday, including one that resulted in a fatality. According to police, additional weather-related fatal accidents occurred on Sunday near Charleston, West Virginia, and on Monday in Winston-Salem, North Carolina. There were two fatal accidents in Kansas over the weekend.

As of Monday evening, more than 2,300 flights had been canceled and at least 9,100 more delayed across the country, according to tracking platform FlightAware. Ronald Reagan Washington National Airport reported that about 58% of arrivals and 70% of departures were canceled.

An additional 15 to 30 cm of snow was forecast for the Mid-Atlantic region on Monday. Dangerously cold temperatures were expected, with overnight lows falling into the single digits (below -12.7°C) by midweek in the central plains and valleys of Mississippi and Ohio.

According to the National Weather Service, 2 to 5 inches (about 5 to 13 cm) of snow was expected in North Texas starting Thursday. Snow could also fall in Oklahoma and Arkansas, with some parts potentially seeing more than 4 inches (about 10 cm) of snow.

School closures were widespread, with districts in Indiana, Virginia, Kentucky, Missouri and Kansas canceling or delaying the start of classes on Monday. Among them were Jefferson County Public Schools in Kentucky, which canceled classes and other school activities for nearly 100,000 students.

Many were left in the dark as temperatures dropped. More than 218,000 customers were without power in Kentucky, Indiana, Virginia, West Virginia, Illinois, Missouri and North Carolina as of Monday evening, according to utility tracking website PowerOutage.us.

In Virginia’s capital, a power outage caused a temporary disruption in the water system, officials said Monday afternoon. Richmond officials urged residents of the city of more than 200,000 not to drink tap water or wash dishes without first boiling the water. The city also urged people to conserve water, for example by taking shorter showers.

City officials said they were working nonstop to get the system back online.