By Karin Matz
CHICAGO (Reuters) - The Denver International Airport was experiencing delays and cancellations on Thursday morning after hail and rain pelted the area Wednesday night during a severe thunderstorm, leaving 1,000 passengers stranded at the airport overnight.
Among those passengers was Wisconsin Governor Scott Walker, who was traveling to the National Governors Association meeting in Salt Lake City.
Walker tweeted, "Got stuck in Denver airport & slept on the floor (did get a pillow & blanket)."
Most airlines reported significant hail damage after the 15 minute storm, according to Laura Coale, a spokeswoman for the airport, who said there were reports of damage to 40 planes.
She said the airport anticipated more delays throughout the day on Thursday.
United Airlines canceled 30 departures out of Denver on Thursday and was checking its aircraft for damage, according a company spokesman.
Wind gusts of 59 miles per hour and one-inch hail were reported at DIA, according to the National Weather Service. The area will be under a flash flood watch Thursday afternoon and through the evening.
"We are expecting some heavy rains, and there could be some hail with the storms," said Byron Louis, program manager for the weather service in Denver.
Elsewhere in the nation some states were getting a brief break from the heat. On Thursday 10 states were under heat advisories or watches, down from earlier in the week when 24 states were on the list.
But the break won't last.
"The big story for the coming weekend will be the building heat," said Jim Keeney, a weather service meteorologist.
A massive heat wave is expected to develop over much of the central and eastern United States with heat index values that could reach 115 degrees.
"It looks like it's going to be a long-term heat wave," Keeney said.
(Additional reporting by Kyle Peterson and Keith Coffman)