Hail experts highlight progress in understanding devastating storms

Scientists brief reporters at the Hail workshop in North America

September 22, 2022 – By David Husansky

Scientists are making substantive progress in better understanding hailstorms, a major step toward improving predictions of billions of dollars in risks, leading experts said at a press briefing Thursday.

Briefed on the 2nd North American Workshop on Hail and Hail Storms, an event hosted by the National Center for Atmospheric Research (NCAR) for U.S. and international hailologists to share updates on important developments in hail research. Hail storms are one of the costliest types of climate disasters, causing $16 billion in damage across North America last year alone.

At the press conference, NCAR Chief Scientist Andrew Hemsfield emphasized the importance of using radars to better detect hail and thus help mitigate damage associated with storms. It highlighted key questions that scientists seek to answer, including the impact of climate change on hailstorms and the processes within a storm that affect the density and size of hail—particularly why some storms generate particularly large and destructive hailstones.

“In a hailstorm, only a very few selected hailstones become the largest,” he said. What are the basic physical processes that select ‘favorite’ hailstones?

Scientists use machine learning and computer simulations to study the many paths of hailstones through a storm. (Photo by Becky Adams Celine, Firske Research Atmospheric and Environmental.)

Becky Adams-Selene, chief scientist at Verisk Atmospheric and Environmental Research, discussed using advanced machine learning and computer modeling techniques to determine why it is so difficult to predict which storms will produce large hail. Her research suggests that the processes that lead to large hail may have more to do with the storm’s structure than with atmospheric conditions such as wind or temperature.

“Large hailstones are hard to predict from a forecasting perspective because every storm is really different, and the same atmospheric environment can produce several types of storms,” ​​she said. “We are using machine learning to identify patterns in tens of thousands of different hail tracks in a storm, with the goal of identifying the conditions that generate the most damaging hailstones.”

Ian Gimanco, senior director of standards and data analytics and research meteorologist at the Insurance Institute for Business and Home Safety, noted that hail is responsible for about 70% of the damage caused by severe thunderstorms, which is much more than the financial losses caused by hurricanes. or lightning. He stressed that society needs to focus on greater resilience in the face of hailstorms, especially with more development taking place in hail-prone areas.

“Our homes are getting wider, they are being built closer, and our communities are more spread out, so there is a lot of material that gets caught in the hail and needs to be replaced,” he said. “We have a big challenge ahead because a lot of the things we have – our homes, our businesses, our cars and so on – are not well suited to dealing with hailstorms.”

Speakers emphasized the importance of gathering more data on hailstorms. They note that there hasn’t been a major US field project studying hail in more than 40 years. Instead, scientists have to rely on the scattered reports of hail that fell on Earth and try to deduce the general characteristics of the storm that produced it. Adams-Selin, Heymsfield and their colleagues proposed a new field project, ICECHIP (Cooperative In-Situ Experiment for Hail on the Plains Group), that would use aircraft, radars and other tools to make detailed observations of hailstorms over the Great Plains and the frontal range of the Rocky Mountains.

“We need better observations so that we can understand the complex processes that occur in a hailstorm, which will lead to better predictions,” Hemsfeld said.

View all news

%d bloggers like this: