Millions across the country are waking up to more severe weather Tuesday, with more than 1,000 flights in and out of the East Coast canceled overnight after thunderstorms struck the region and a deadly heat wave smothered the South.

More than 1,100 flights in, to and out of the United States were canceled as of Tuesday afternoon, with almost 280 of those going to and out of Newark Liberty International Airport, according to the online tracker FlightAware.

LaGuardia Airport had more than 230 cancellations, while John F. Kennedy International Airport had more than 90 and Boston Logan International Airport had more than 110.

Newark, LaGuardia and JFK all warned on Twitter that weather conditions were causing flight disruptions, delays and cancellations as they warned travelers to allow extra time and contact their airlines for updates.

The National Weather Service warned that widespread clusters of showers and thunderstorms would hang over the region into the early hours of Tuesday, with another front expected to bring more severe weather.

‘It’s definitely an adventure’

For Toya Stewart Downey and her family, the severe weather has caused major disruption, turning what was meant to be a direct flight from New York to Minneapolis into a potentially dayslong journey.

Stewart Downey, 57, and her two children, Cameron, 24, and Dallas, who will soon turn 16, had been in New York to celebrate the upcoming birthday. When they arrived at LaGuardia around 4 p.m. ET for their 6:30 p.m. flight back to Minneapolis, they noticed a string of flights being canceled due to severe weather, but they held out hope their own journey would not be affected.

After hours of waiting, they learned their own flight had been delayed and then canceled due to severe weather, with the next flight available not until Thursday.

"We said we'll take any flight to any city," Stewart Downey, a communications director for a school district in Minnesota, said in a phone interview.

She said she and her family ended up having to take a Lyft, which she said Delta Air Lines paid for, all the way to Hartford, Connecticut, a nearly 2-hour drive, in hopes of catching a flight to Detroit and then, finally, to Minneapolis.

The journey could result in the family not arriving at their destination until Wednesday, she said.

“We sincerely apologize to our customers for the inconvenience to their travel plans as weather and air traffic control challenges have impacted our operations," a Delta spokesperson said. "We are working to get them quickly and safely to their destination and encourage them to use the Fly Delta app for the latest updates to their flights.” 

The family had commitments at home in Minneapolis, Stewart Downey said, adding: "We all want to get back as soon as possible."

“It’s definitely an adventure,” Cameron said of the unexpected journey to get to home.

She said that after spending almost 9 hours at LaGuardia, and then having to take a Lyft in the early hours of Tuesday, her family was "tired, but I think there's enough to do and figure out that it's not hard to stay awake either."

Had they waited for the Thursday flight, she said, it would have "kind of felt outlandish that suddenly, I would have to be in New York for an entire week."

More severe weather on the way

More severe weather is expected in the area, with the weather service warning that a front extending from parts of the Great Lakes/mid-Atlantic to the Southeast and then to the southern Plains was also moving toward the East Coast.

The associated front was expected to bring showers and moderate to severe thunderstorms over parts of New York state, Pennsylvania, Maryland, Delaware, Virginia and North Carolina, with a marginal risk of severe thunderstorms over parts of the Northeast/mid-Atlantic through Wednesday morning, the weather service said in a later update.

“The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a minimal threat of tornadoes,” it said.

Already, photos and videos shared on social media appeared to show hail storms in areas in Pennsylvania and North Carolina on Monday.

Meanwhile, New York Gov. Kathy Hochul warned Monday that “severe weather is expected across the state this week, bringing with it persistent rain, thunderstorms and the potential to cause flash flooding.”

“Our state agencies are preparing emergency response assets and we are in close contact with local governments across the state to ensure they are prepared,” she said. “I encourage all New Yorkers to monitor their local weather forecasts, pay attention to alerts and plan accordingly.”

Along the western end of the front moving eastward, showers and severe thunderstorms were expected to develop over parts of southern Kansas, Oklahoma, extreme southwestern Missouri and northwestern Arkansas, the weather service said, adding that an enhanced risk of severe thunderstorms was in place for parts of the central and southern Plains through Wednesday morning.

"The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes," along with the threat of "two-inch or greater hail," it said.

Showers and severe thunderstorms were separately expected over parts of South Dakota and Nebraska.

Potentially record-breaking heat in Texas

As many braced for stormy conditions, residents of Texas and neighboring states continue to face severe heat, which turned deadly after two people died hiking in Big Bend National Park.

Excessive heat warnings with triple digit heat indices were expected to continue Tuesday, bringing potentially record-breaking temperatures, the weather service warned.

"The stagnant upper-level ridge over the south-central U.S. and resultant multi-week heatwave will not only continue but begin to expand in reach over the next couple of days as the ridge builds northeastward," the weather service said in an online update.

"Highs from southeastern Arizona through southern New Mexico and into Texas will remain in the 100s Tuesday, with upper 90s to 100s spreading northward into the Central Plains and Middle/Lower Missouri Valley as well as east into the Lower Mississippi Valley Wednesday," it said.

Some daily record-tying or even potentially record-breaking highs were "once again possible for portions of Texas and the Lower Mississippi Valley. "

Recovery after deadly storm

The death toll from severe weather across the country also continues to mount, with at least three people killed after a storm front wreaked havoc Sunday in the Midwest and the South.

One person was killed when a tornado felled a house in Martin County, Indiana, according to officials, with Cameron Wolf, director of Martin County Emergency Management, confirming the death and saying the victim’s injured partner was airlifted to a hospital.

In Arkansas, two people were also killed when a tree fell on a home in Carlisle, The Associated Press reported. A third person was also injured in the incident, according to the outlet.