Atmospheric researcher Anthony Bernal Ayala, working within a specialized cold laboratory in Boulder, Colorado, meticulously slices hailstones with a band saw, revealing intricate layers of icy growth akin to the annual rings of a tree. These frozen strata—distinguished by their clarity or cloudiness, thickness or thinness—provide a remarkable chronicle of the atmospheric conditions present during the hailstone’s formation. A clear layer signifies slow freezing, allowing water molecules to align neatly, while a cloudy layer indicates rapid freezing, trapping air bubbles and creating an opaque appearance. Bernal Ayala’s analysis extends to the crystalline structures, embedded particles, and isotopic signatures preserved within these layers, unlocking a wealth of historical meteorological data. "All that information can tell you a wonderful story of how the hailstone was growing, but nobody—not until now—was able to tap into that history," explained Bernal Ayala, affiliated with Atmospheric and Environmental Research, part of the JANUS Research Group.

Bernal Ayala’s pioneering research, conducted at the National Center for Atmospheric Research (NCAR), is a crucial component of a significant, long-term initiative dedicated to understanding one of the most financially damaging weather phenomena. The ultimate goal of these investigations is to enhance protections for lives and property against the destructive power of hailstones as they descend, inflicting damage upon roofs, devastating agricultural crops, and marring vehicles.

The economic impact of severe thunderstorms, with hail being a primary contributor, has escalated dramatically. According to the Insurance Institute for Business and Home Safety, annual losses from severe thunderstorms between 2023 and 2025 exceeded $50 billion nationwide, more than doubling the figures from just a decade prior. Hail alone is responsible for an estimated 60% to 80% of this extensive damage. In Colorado, a state particularly susceptible to hailstorms, this phenomenon, rather than wildfires, is now the leading driver of escalating insurance premiums. Compounding these concerns, researchers anticipate that climate change will lead to an increase in the frequency and size of damaging hailstones, further intensifying the financial burden. "It’s going to just keep getting costlier and costlier," Bernal Ayala cautioned.

Even fundamental questions surrounding hail formation and behavior have historically been challenging to address through scientific inquiry. However, a renewed focus on hail research, bolstered by the first substantial U.S. field campaign dedicated to studying hail in over four decades, promises to fundamentally alter our understanding. This ambitious endeavor, known as ICECHIP (In-situ Collaborative Experiment for the Collection of Hail In the Plains), received an $11 million grant from the National Science Foundation in 2024, a timely investment prior to significant budget reductions impacting the foundation in 2025.

Over a concentrated six-week period in the spring of 2025, approximately 100 scientists and university students embarked on a mission to track and study hailstorms across the Central Plains and the Front Range of Colorado, spanning from the Canadian to the Mexican borders. The campaign employed a suite of advanced technologies, including mobile radar units to monitor storm development and drones for aerial reconnaissance. Researchers utilized high-speed cameras to capture detailed images of falling hailstones, deployed a disdrometer to measure their impact velocity, and analyzed imprints left on foam pads to determine their distribution and size. Specialized collection funnels were used to gather intact samples, which were then subjected to tests measuring their structural integrity. Adding an international dimension, scientists from the Australian Bureau of Meteorology launched golf ball-sized sensors via balloons into storm systems. These sophisticated probes collected real-time data on their descent speed, the rate of ice accretion, and even recorded the acoustic signatures of water droplets and hailstones impacting their surface through an integrated microphone.

"This has really been the first time where we’ve been able to do a real comprehensive look at hail on the ground, hail aloft, the storm itself, the environment around the storm—just everything all at once," stated Becky Adams-Selin, the lead investigator for ICECHIP and a principal scientist at Atmospheric and Environmental Research, JANUS Research Group. This holistic approach is unprecedented in its scope and aims to provide a more complete picture of hail formation and evolution.

The valuable samples collected during the ICECHIP campaign were meticulously preserved in 26 cooler-sized boxes and transported to NCAR. This institution, a globally recognized center for atmospheric and climate research, has a long history of studying hail, dating back to significant campaigns in the 1970s that investigated Soviet claims of hail suppression technology. Researchers emphasize that the specialized facilities at NCAR are unique, with the backup plan for storing the ICECHIP samples involving a walk-in freezer typically used by a fast-food restaurant, highlighting the critical need for dedicated scientific infrastructure.

However, the future of NCAR itself has faced considerable uncertainty. In late 2025, the Trump administration announced plans to dissolve the center and relocate its operations. The University Corporation for Atmospheric Research (UCAR), which manages NCAR, filed a lawsuit in March against the administration, alleging that the move was politically motivated and intended as retaliation against Colorado for its retention of mail-in voting systems and Governor Jared Polis’s refusal to release a former county clerk implicated in election security breaches. A federal judge has since issued a temporary injunction preventing the administration from dismantling NCAR, with the government mandated to respond to the lawsuit by September 30. "I can’t even quantify the impact that it would have to our community if we lost NCAR," remarked Victor Gensini, a professor of meteorology at Northern Illinois University, emphasizing the institution’s vital role. "They are the beating heart."

Prior scientific research has consistently pointed to the influence of climate change on hail events. Warmer ambient temperatures, while potentially causing smaller hailstones to melt before reaching the ground, can simultaneously fuel more powerful updrafts within thunderstorms. These intensified updrafts can suspend hailstones aloft for longer periods, allowing them to accumulate more ice and grow to larger, more destructive sizes, thus increasing the likelihood of severe hail events. This trend is already evident, with a record-breaking hailstone measuring over five inches in diameter recovered in Yuma County, Colorado, in 2023. That same year, Colorado recorded 176 reports of hail two inches or greater, more than double the previous record of 91 reports set in 2018, according to the Colorado Climate Center.

Scientists acknowledge the complexity in attributing the rise in hail damage solely to an increase in large hail versus the concurrent expansion of development in historically hail-prone regions. This phenomenon, where a growing human footprint intersects with increased weather risks, is often referred to as the "expanding bull’s-eye effect." Gensini, a principal investigator for ICECHIP, highlights the dramatic development boom east of the Front Range along Colorado’s Interstate 25 corridor. The population of the Fort Collins metropolitan area, for instance, has doubled since 1990 to approximately 375,000 residents, according to U.S. Census Bureau data. This pattern of urbanization is being observed across the Western United States, as previously undeveloped or sparsely populated areas become densely populated and increasingly valuable targets for severe weather events like hailstorms. "Colorado is the poster child for what I expect the next 25 years to look like for hail," Gensini stated, underscoring the region’s vulnerability.

In response to escalating hail damage, Fort Collins became one of the first cities to implement hail-specific roofing requirements for new construction and renovations in 2019. Marcus Coldiron, the city’s chief building official, noted that these regulations were partly a reaction to the substantial volume of damaged roofing materials sent to landfills following a catastrophic hailstorm in 2018. While the long-term effectiveness of these mandates is still being assessed, Coldiron reported a decrease in permits issued for roof replacements and a corresponding reduction in shingle waste. However, Fort Collins has not yet experienced another hailstorm of the magnitude seen in 2018, making a definitive evaluation challenging. Nevertheless, a growing number of communities along the Front Range are incorporating impact-resistant shingles into their building codes, and Colorado legislators recently passed a bill providing grants to residents who install more resilient roofing materials.

Researchers involved in the ICECHIP project are also investigating how to improve building materials in light of increasingly common billion-dollar weather-related losses from single storm events. "The dollars are simply piling up so fast," observed Ian Giammanco, a lead research meteorologist at the Insurance Institute for Business and Home Safety, a key partner in the ICECHIP initiative. "We’re still trying to understand how do we get the best materials onto roofs, onto people’s homes, onto businesses to actually start shaving off these losses." This focus on resilient infrastructure is becoming increasingly critical as the threat posed by severe weather continues to grow.