Dewey Kahawai was asleep when he heard a knock on his bedroom window.
“I sprang out of bed and thought, ‘Oh my gosh, someone’s trying to get into my house,’” he said.
That was soon followed by thumping on the roof as a hailstorm tore through Milliken, Colo., a small town about 50 miles north of Denver. Residents reported ice chunks nearly the size of baseballs.
Just a few years ago, Kahawai had to replace his roof after another storm. This time, in late June, his house was unscathed. But by morning, his phone was buzzing with calls and texts. Kahawai runs his own company, American Pride Auto Glass. For two straight weeks, he worked 14-hour days, crisscrossing town.
“There were people's cars that were literally destroyed,” he said. “Three- or four-inch diameter holes through the glass on their vehicles; front windshields with six, eight hits.”
He estimated he alone responded to hundreds of thousands of dollars in damage. A month after the storm, Milliken looks mostly back to normal. But the hints of the storm are still there: signs for repair businesses dot lawns; bundles of shingles are piled on roofs ready to be replaced; car doors look like they’ve absorbed a few punches.
Mounting costs
Ian Giammanco, a lead research meteorologist at the Insurance Institute for Business and Home Safety, said hail impacts to cars, crops and roofs add up.
“It's not as big of a life safety threat as, say, a storm surge or flash flooding or a tornado,” Giammanco said. “But it happens every single year and it’s costing us just tens of billions of dollars.”
The costs from hail are increasing, reaching nearly $50 billion in 2023, according to Giammanco. The trend is partly explained by more people moving to places with hailstorms. And while research points to fewer hailstones overall with climate change, the hail that does fall could be more destructive.
In Colorado, hail is a bigger driver of rising insurance premiums than wildfires.
“If you look at this growing loss picture, this is something that is not sustainable at this rate,” Giammanco said.
Perfect spheres?
Despite hail’s climbing toll, scientists still have fundamental unanswered questions.
“How fast does a hailstone fall? How does it melt?” said Becky Adams-Selin, a scientist at Atmospheric and Environmental Research. “Again, all things that seem pretty basic, but are surprisingly difficult to try to unpack.”
Many existing weather models assume hailstones are perfect spheres, but researchers know that’s rarely the case.
To find long sought answers, Adams-Selin is leading a huge team of researchers, including Giammanco, on the largest study of hail in the U.S. in 40 years. The project, called the In-situ Collaborative Experiment for the Collection of Hail in the Plains, or ICECHIP, is supported by a $11 million National Science Foundation grant. It includes researchers from Colorado State University and the University of Colorado Boulder.
For six weeks this summer, scientists chased hailstorms across the Great Plains and Mountain West, where hail is most common.
“There were some fantastic storms,” said Adams-Selin.
Using radar, the team would predict the path of a storm and deploy an array of equipment across several miles. That included foam pads to quantify hail’s force, disdrometers to capture raindrop size andfunnels to collect falling hail and measure its speed. Giammanco’s team even brought cutting-edge roofing shingle designs to test their real-world durability.
“And then we'd get back out of the way and let the hailstorm run over it,” Adams-Selin said.
They also snapped photos with high-tech cameras and flew drones into clouds. After storms passed, researchers piled out of cars and scooped hailstones into freezers.
Uncovering clues from the hailstones
Now, 26 boxes of hailstones collected from as far south as the Mexican border and as far north as Canada are stacked in a cold lab at the National Center for Atmospheric Research in Boulder, Colo.
Inside the closet-size freezer, Anthony Bernal Ayala, a post-doctorate researcher clad in a full-body puffy suit, examined the hail preserved in Ziploc bags. Over the next few months, he'll record each one’s size and weight, take 3D scans and even slice some open with a band saw.
“A hailstone is kind of like its own lab,” Bernal Ayala said. “It’s a chronicle of time that will save its information within its crystalline structure.”
The big insights, he said, will come from matching each hailstone with the storm data. That’ll uncover why certain ingredients in the sky – like temperature, humidity, wind – produce a different recipe of hail that falls to the ground. Researchers said the information will drastically expand the knowledge scientists currently have about hail.
“It's going to blow it out of the water,” said Adams-Selin.
The results could help better predict hailstorms from radar data and give more detailed warnings. Beyond just forecasting the maximum size of hail, they could also predict how long it’ll fall and whether it’ll be pushed by wind.
“That would be awesome,” said Adam-Selin, noting it could provide just enough notice to pull cars into a garage, drape netting over crops or find shelter.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
