World's Heaviest Hailstone Weighs Over a Kilogram: How Do They Get So Big?

A new method using real hailstones and CT scans has revealed how they grow.

On April 14, 1986, the Gopalganj district of Bangladesh was hit by one of the most devastating hailstorms in recorded history, killing 92 people. According to the World Meteorological Organization (WMO), the massive ice chunks weighed up to 1.02 kilograms (2.2 pounds), setting a harrowing world record.

More than three decades later, as climate change increases extreme weather events, giant hailstones continue to appear. A new study looks at a hailstorm that rocked Catalonia, Spain, in 2022 to learn more about how the giant ice balls form and grow.

Climate change increases extreme weather events, giant hail continues to appear.

Catalonia Hailstorm 2022: Clues from giant ice samples

A 2022 storm in Catalonia left behind some surprisingly large hailstones, some measuring up to 12 centimeters (4.7 inches) in diameter. What's more, some local residents preserved the ice in their freezers, providing scientists with a valuable opportunity to study it.

Using computed tomography (CT) scanning, a team at the University of Barcelona, ​​led by Professor Xavier Úbeda, obtained detailed images of the internal structure of hailstones without destroying the sample.

'This technique provides information about the inner layers, allowing us to observe the evolution of hail ,' Professor Úbeda shared.

Perfectly spherical hailstones also have complex structures.

Exploring the Internal Structure of Hail

CT scans show that even perfectly spherical hailstones have complex structures, with irregularly developed layers. The inner core, or embryo, is often not located in the center but off to one side, reflecting the way hailstones form under the influence of various atmospheric factors.

'This technique allows us to analyse the density and structure of the rock layers, providing insight into the stages of hailstone development,' added co-author Professor Javier Martin-Vide.

Major step forward in extreme weather forecasting

The study demonstrated the effectiveness of a non-invasive method for analyzing hail, opening up the potential to improve the forecasting of hazardous weather events.

'This is the first time we have been able to directly observe the entire internal structure of hail. This technique could help predict more accurately when dangerous storms will occur,' said Carme Farnell Barqué, a researcher at the Catalonia Meteorological Service.

Climate change and the future of hail

Climate change is increasing the frequency and severity of extreme weather events, including hail. The new findings from this study not only provide further insight into the formation of giant hailstones, but also offer hope for better preparedness against future natural threats.

The study, published in Frontiers in Environmental Science , marks a major step forward in the field of meteorology. From the painful lessons of 1986 in Bangladesh to the scientific achievements of 2022 in Spain, humans are constantly trying to understand and adapt to the harshness of nature.