Storms will rumble into Memorial Day weekend as nearly 44 million travel for the holiday

Nearly 44 million people are traveling this Memorial Day weekend, but severe spring weather will put a damper on some of the festivities with showers and thunderstorms forecast across the country along with scorching heat in South Texas and Florida.

Summer fun is already kicking off with nearly 3 million people screened Thursday at Transportation Security Administration checkpoints — the second highest screening volume in the agency's history. The busiest airports so far are in Atlanta, Dallas, Denver, Chicago and Los Angeles.

The Federal Aviation Administration said last week that it is anticipating Memorial Day weekend to be the busiest since 2010 with 53,515 flights Thursday and 50,129 Friday.

But the skies may not be on revelry’s side as heavy rain and severe thunderstorms are forecast to continue from the Midwest to southern Plains on Friday, with extreme rainfall rates of up to 2 inches per hour.

Forty-five million people are at risk from Chicago all the way down to Austin, Texas, with biggest risks being damaging hail, strong wind gusts and a few possible tornadoes.

A severe thunderstorm watch has been issued for parts of Illinois, Iowa and Wisconsin through 1 p.m. local time (2 p.m. ET) with threats of tornadoes and scattered wind gusts up to 75 mph.

That means major airports in Chicago, St. Louis and Dallas-Fort Worth could all see major delays.

Come Saturday, scattered storms will head into the Northeast. All the while, another round of severe weather will develop across the central and southern Plains before shifting into parts of the mid-Mississippi and Ohio valleys, according to the National Weather Service.

Sixteen million people will be at risk of severe weather Saturday affecting Kansas, Oklahoma and Missouri with threats of strong tornadoes, hail and winds over 75mph likely, as well as nocturnal tornadoes in west-central Oklahoma and south-central Kansas. Cities to watch for storm damage include Oklahoma City, Kansas City, and Wichita.

Another outbreak of severe weather is possible Sunday, with 39 million people at risk of strong tornadoes, damaging hail and winds up to 75 mph. The cities with the greatest threat include St. Louis and Indianapolis.

All the while, “dangerous and potentially record-breaking heat” continues across South Texas, the Gulf Coast and southern Florida through Memorial Day, the NWS said.

Heat advisories are in place through 7 p.m. CT (8 p.m. ET) for parts of southern Texas anticipating heat index values up to 114.

On Memorial Day itself, the East Coast will see rain and thunderstorms, the Midwest a mix of sunshine and rain, and the South will be very hot and humid. Airports on that day in Chicago, Detroit, New York-Newark, Philadelphia and Washington will likely see delays.

The weekend weather comes after a week of wild weather across the Midwest and South. Tornadoes have been reported every day since Sunday, with another 23 reported Thursday.