All flights at JFK Airport are grounded as NYC is put on 'red alert' for severe thunderstorms - after death toll in southern summer storms reaches 21

All flights were grounded at New York's JFK this afternoon - an occurrence attributed to ongoing thunderstorms seen across much of the US, the FAA said.

The travel chaos comes as citizens in Texas, Arkansas, Kentucky, Missouri and Tennessee were all hit over Memorial Day Weekend by a bevy of twisters, heavy winds and flooding, which, so far, have killed at least 21 people.

Among them were four children, spurring a statewide emergency declaration in Kentucky as the mass of severe weather was set to move east. 

As a result, more than 100million across the East Coast are now at risk, with 4,600 flights delayed. This includes the well-traveled Tristate, where thunderstorms - and even the odd tornado - could be in the forecast. Another 409 flights were canceled.

New York City residents were already told to brace for a red alert from 6pm Monday due to the threat of incoming storms, while the FAA's ground stop is expected to last through 3:45pm.   

The red alert, meanwhile is expected to last into the early hours of Tuesday, during which New Yorkers will be bombarded torrential rain, hail, and gusty winds, which may produce flash flooding.

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All flights were grounded at New York's JFK this afternoon - an occurrence attributed to ongoing thunderstorms seen across much of the US, the FAA said. Some halted flights are seen there Monday afternoon

The travel chaos comes as citizens in Texas , Arkansas , Kentucky , Missouri and Tennessee were all hit over Memorial Day Weekend by a bevy of twisters, heavy winds and flooding, which so far have killed at least 21 people. Seen here, a tornado in Eddyville, Kentucky, Sunday

Seven have already died in Texas, eight in Arkansas, two in Oklahoma and four in Kentucky, while a fifth person was said to be 'fighting for their life' by the Blue Grass State's governor in a press conference Monday.

'Sadly we can confirm that we have lost at least four Kentuckians from last night's storm,' Gov. Andy Beshear said at the emergency conference from the Kentucky Emergency Operations Center.

'That means we know that there are at least four families this morning that have suffered the loss of a loved one less than 24 hours ago that are hurting. 

'We ought to rally around them and do everything we can to carry them and the days the weeks and the years to come,' he added - before revealing the uncertain fate for the fifth person.

In New York, flights were grounded at JFK early in the afternoon, the FAA said.

The agency thus issued a ground stop at JFK - the city's most trafficked airport - around 2:30pm, as rain began to stream down after some showers in the morning.

The stop, as of writing, is expected to last late into the afternoon, while not-so-nearby LaGuardia saw all its flights grounded around 1 pm - though that order has been lifted. 

Officials there, however, still warned to expect an average of 100-minute delays to last through the night, something they said could last as long as three and a half hours.

At Newark Liberty International in New Jersey, flights were experiencing 15 minute delays around 11:30 am, the FAA further confirmed. Those delays ceased around 1pm, but more are expected not only at Newark, but at JFK and LaGuardia through 7 pm.

At around 2:45pm, a Special Weather Statement was issued for Queens & Brooklyn, where city leaders instructed residents to stay indoors amid 'strong thunderstorms and wind gusts up to 40 mph. 

'Gusty winds could knock down tree limbs and blow around unsecured objects,' the alert added. 'If outdoors, consider seeking shelter inside of a building.'

In New York, flights were grounded at JFK early in the afternoon, the FAA said. The agency thus issued a ground stop at JFK - the city's most trafficked airport - around 2:30pm, as rain began to stream down after some showers in the morning

The stop, as of writing, is expected to last late into the afternoon, while not-so-nearby LaGuardia saw all its flights grounded around 1 pm - though that order has been lifted. One of JFK's runways is seen soaked Thursday afternoon

At another transit hub located along the Mid-Atlantic, Chicago, a plane’s engine literally caught fire in Chicago O’Hare Airport just before 3pm - shortly after two rounds of severe storms led to Severe Thunderstorm Warnings and even Tornado Warnings in parts of the city.

The incident - which is currently being addressed - saw all airport operations suspended, after only 28 flights had been canceled beforehand due to increment weather.

Meanwhile, more than 4,000 flights nationwide currently delayed, with no flights canceled at Chicago's alternative airport Midway International.

Before the unspecified plane caught fire on a runway at O'Hare, a total of 1,024 flights had been delayed. At Midway, 162 flights were delayed in a span of 24 hours.

In the South, the four fatalities so far confirmed included a 67-year-old woman in Mercer County, a 62-year-old woman in Hardin County, a 48-year-old woman in Hopkins County, and a 34-year-old man in Jefferson County - all of whom went unnamed.

This brings the nationwide death toll over the Memorial Day Weekend up to 21, after a woman and two of her children saw their home struck by a tornado Saturday night in Valley View, Texas, killing all three.

'It was a really terrible thing,' Benito Esparza, the sole survivor's brother, told CNN in Spanish Monday, of the fate of sister-in-law Laura Esparza and her children Marco, 10, and Miranda, 16. 

His brother, Refugio Esparza, survived the tornado, but suffered a broken leg and pelvis. 

'He lost three people, his wife and two kids,' Benito Esparza said. 'It's not easy.'

The mass of severe weather had been forecast to move east, affecting more than 100million across the East Coast. New York City (seen here Monday Morning) is among the metros at risk

Meanwhile, seven people are dead in northern Texas, wreckage was strewn across a property Sunday the day after a deadly series of tornados hit Valley View and much of the rest of the central United States

One of at least 20 powerful tornadoes spotted Saturday and Sunday - this one seen in North Texas later Saturday in Cooke County

Another eight have died in Arkansas, two in Oklahoma and four in Kentucky - with a fifth person 'fighting for their life' in the Blue Grass State,  Gov. Andy Beshear revealed in a press conference called Monday.

The update brought the nationwide death toll over the Memorial Day Weekend up to 21, after a woman and two of her kids saw their home struck by a tornado Saturday night in Valley View, Texas. Pictured: Laura Esparza (center) and kids Miranda, 16, and Marco, 10

He added how two of Refugio's older children were not at the home at the time of the tornado, which first surfaced outside the Dallas-Fort Worth area overnight Saturday, and saw at least seven killed. 

That made it the deadliest tornado in state history since 2015 - leaving residents to dig through the tons of rubble and debris left behind.

That distinction was not lost on Benito, who spent Monday morning sifting through the remains of his brother's home for what was left.

'It's a very big disaster for everyone, as you can see,' said Esparza of storm's ongoing effect, as recovery efforts to continue.

He further recalled how his three family members died after their trailer was thrusted across a street - a scene that was sadly not unique across the country Saturday and Sunday.

There were more than 20 tornado reports within that span ranging from Texas to Missouri, bolstered by several detailing the damage left behind and, of course, the casualties.

Elsewhere in Texas, violent storms overtook 18-wheelers, destroyed homes, and brought down power lines - even crushing a Shell station in Cooke County.

This left 125 people trapped for a period Saturday night, officials said - revealing how all miraculously were retrieved uninjured.

Several of the deaths were reported in Valley View in Cooke County, Texas, near the Oklahoma border, where a tornado Saturday night plowed through a rural area near a mobile home park

That made it the deadliest tornado in state history since 2015 - leaving residents to dig through the tons of rubble and debris left behind. The area as it was Sunday, as recovery efforts persist

Also hit was nearby Denton County, where search and recovery efforts are still underway

There, the storms inflicted some of their worst damage  - in a region spanning from north of Dallas to the northwest corner of Arkansas.

 The system then threatened to bring more violent weather to parts of the Midwest, affecting counties in Arkansas, Oklahoma, and Kentucky.

A slew of deaths in those states were recorded Sunday, mostly from falling trees.

One such death was confirmed in Mercer County early Monday, before the governor confirmed four overall had died.

That person was pronounced dead along with another in Louisville, where Mayor Craig Greenburg confirmed it was a storm-related death. 

Hours later, the state's governor revealed the tally was up to four - a number that very well could still rise, he said.

The trees and homes damaged in those states were hit not only by tornados, but by winds that reached 135mph in some places, leaving some 500,000 without electricity across Arkansas, Oklahoma, Kentucky, and Texas.

Out of the 21 who died, seven of the storm-related deaths came from Cooke County, Texas, as well as eight across a range of areas in Arkansas.

Juana Landeros, who rode out deadly tornado with her husband and her 9-year-old son when it rolled through the previous night, salvages items from her destroyed home Sunday

More damage in Denton county is seen here, as much of the central US was not spared by the twisters

A man looks at a damaged car after a tornado hit the day before, Sunday in savaged Valley View

The storms left a wide trail of destruction Sunday, before moving northeast into Oklahoma, Arkansas and Kentucky

Guadalupe Virgin statue lays among the rubble of a destroyed home in Valley View, which was one of the town's most affected by the tornados and more than 100pmh winds

Wreckage is strewn across a property the day after a deadly series of tornados hit the central United States, in an aerial view over the north Texas town near Oklahoma

Several cars are seen heavily damaged outside the remains of a Shell gas station, after it collapsed in on itself trapping more than 100 people taking shelter. Miraculously, they all survived unscathed, officials said

Another two were recorded in Oklahoma's Mayes County, where trees have been uprooted by twisters all over town, with powerlines down and structures flattened.

In Arkansas, The National Weather Service in Tulsa said a survey team found EF-3 damage near the town of Decatur, where at least one tornado hit.

Another two hit Beaver Lake and others in Benton County, where three of the eight casualties were recorded. 

A 26-year-old woman, moreover, was found dead outside a destroyed home in Olvey, as recovery efforts in all four states continue.

In addition to the incident described by Esparza, the dead in Texas included two other children, ages 2 and 5, and three other family members also found together in a tornado-struck home in Cooke County.  

The severe weather, meanwhile, is not over, after it pushed east into the Midwest and the Ohio Valley over the course of Sunday.

Missouri was the state hit hardest Sunday, where residents of Mehlville reported a violent storm and possible tornado that destroyed dozens of houses.

This saw cities like Chicago, Indianapolis, Nashville, Tennessee, St. Louis, and Cincinnati hit by strong showers and damaging winds, but no tornados, as of writing.

It is set to finish off today over the East Coast, where risk of severe weather was issued to mid-Atlantic strongholds such as Baltimore; Washington, D.C.; and Charlotte and Raleigh, North Carolina.

Damage is seen to Tom Jones' home after the roof blew off during a storm Sunday in nearby Claremore, a community just across the border in Oklahoma

view storm damage to their next door neighbor's home in the small town, which is located in the foothills of the Ozark Mountains

People view more of the storm damage Sunday in the same community, after the weather moved east to other states

Two deaths were recorded in Oklahoma's Mayes County (seen here Sunday), where trees have been uprooted by twisters all over town, with powerlines down and structures flattened

People view the damage at the town's First Baptist Church, after a curfew was put into effect the night before

Businesses in Arkansas were also damaged from the storm, with Home Town Flea Market in Rodgers left in ruins Sunday

Eight people overall died as a result of the weather in the state, which left the city in Benton county 'unrecognizable', officials said

Missouri was the state hit hardest Sunday, where residents of Mehlville reported a violent storm and possible tornado that destroyed dozens of houses

Meanwhile, clean-ups in several counties in those five states continue, as officials continue to look for any others hurt by the disasters

There, 27 million people are at risk of strong to severe thunderstorms, with more than 110 million people are at risk of severe weather in general.

That includes south of New England, where there is a level 2 out of 5 threat. 

Meanwhile, Philadelphia, Baltimore and Washington, DC, are at risk for tornadoes, but the chances for any to develop are low, officials said.

The travel hubs of Atlanta, New York, and Philadelphia will now have to contend with the prospect of damaging storms and even tornados - though the latter is more unlikely.

This led to the litany of delayed and canceled flights Monday, just as Memorial Day winded to a close.

Travelers are urged to check the current weather conditions of the states they are heading to.