Communities from Texas to New York were picking up the pieces Tuesday after a devastating holiday weekend brought tornadoes, storms, and heavy rain that killed at least 24 people and left hundreds of thousands without power.
The period of severe weather is still not over for Texas, where at least seven people were killed in Cooke County as a result of this weekend's storms. The state could expect more damaging storms through Tuesday.
Over 780,000 utility customers were without power Tuesday morning, according to Poweroutage.us.
National Weather Service offices in Kentucky and Arkansas sent out teams to survey the wreckage. They found damage consistent with EF3 strength tornados — the third highest rating on the enhanced Fujita scale that measures tornado intensity, consistent with winds of up to 165 mph.
The office in Paducah, Kentucky, said it was consulting with experts internally to determine whether the tornado should be classified EF4, the second highest rating, used when winds are between 166 and 200 mph.
Drone camera footage showed the sheer extent of the storm damage in Paragould, Arkansas, where homes had lost roofs and some structures were almost entirely demolished.
The weather service's damage survey team in Louisville, Kentucky, confirmed two EF1 tornadoes touched down Sunday, with wind speeds of up to 90 mph.
There were ground stops at Dallas Fort Worth International Airport and Dallas Love Field Airport on Tuesday morning.
A ground stop at Hartsfield-Jackson Atlanta International Airport added to travel chaos over the holiday weekend, with airport delays topping 5,000 at one point Sunday night, according to FlightAware.com's so-called Misery Map.
The Transportation Security Administration said that Friday was the single busiest day at U.S. airports on record, with 3 million passengers screened, beating the mark set at Thanksgiving last year. The AAA also estimated that some 38 million drivers took to the roads over the weekend, also a record.
Memorial Day brought severe, driving rains with very little visibility to Iowa, social media videos show. Hailstones the size of golf balls could be seen clattering off vehicles in Oak Cliff, a suburb of Dallas, Texas.
Texas is bracing for "strong to severe" storms expected across much of state Tuesday, potentially bringing significant damaging winds and large hail, the weather service said in a forecast. At least 25 million people, including some in Oklahoma, are under some form of weather warning.
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"Merging cells and clusters of storms are also likely to contain intense rainfall rates capable of triggering several flash floods, particularly for areas just west of Dallas-Fort Worth and north of Austin," it said.
Thunderstorms and flash flooding could become a hazard from the Texas Panhandle to the Gulf Coast, the agency's note said.
Video on social media showed strong winds and heavy rains in Lewisville, Texas, about 28 miles north of Dallas.
A hailstorm Monday was so strong in Hurst, Texas, in the Dallas-Fort Worth metropolitan area, that it breached the roof of a Walmart store, prompting shoppers to use nearby products to provide shelter, according to videos uploaded to Instagram.
The extreme heat that has seen much of Texas and the Gulf Coast reach three-figure temperatures in the last few days is finally softening, but the index — a measure of how hot it feels — could still reach 115 degrees Fahrenheit on Tuesday, the weather service said.
Officials and neighbors in Jackson County, Colorado, where rancher Mike Morgan and 34 cattle were killed in a lightning strike Monday, said he will be "extremely missed."
"It's not just the family. It's that broader community in Jackson County," rancher Janie Vanwinkle told NBC affiliate KUSA of Denver.
As for the rest of the week and beyond, the first signs are emerging that this hectic and historic tornado season — there were 461 tornado reports just in May — could be dying down.Â
— Mirna Alsharif contributed.