Impressive masses of ice falling from the sky, capable of destroying crops, damaging roofs or even putting lives in danger: the largest hailstones in the world fascinate as much as they worry. From Asia to the Americas, these true natural records find their origin in extreme and perfectly orchestrated atmospheric conditions. But how does nature manage to form these icy giants, sometimes heavier than a pétanque ball?
Landmark hailstone records
Giant hailstones, while extraordinary, are not uncommon in regions prone to supercell thunderstorms. The record for the heaviest hailstone goes back to a storm in Bangladesh in 1986, where a 1.02 kg specimen was recorded in the Gopalganj district. This phenomenon, recognized by Guinness World Records, caused 92 deaths, highlighting the destructive impact of these masses of ice.
In the United States, the Midwestern plains are particularly exposed. In Vivian, South Dakota, an 8-inch-diameter hailstone fell in 2010, damaging dozens of buildings.
In Argentina, the town of Villa Carlos Paz experienced a hailstone fall estimated at 18 cm in diameter in 2018, marking a potential record in the southern hemisphere according to Sciences et Avenir.
These events demonstrate that giant hailstones, although often associated with the United States, can occur in a variety of climates, from South America to Asia.
The stages of formation of the largest hailstones in the world
The formation of hailstones requires cumulonimbus clouds, these massive storm clouds capable of rising up to 12 kilometers in altitude. Powerful updrafts, characteristic of supercell thunderstorms, play a crucial role.
These currents keep supercooled water droplets (liquid water at temperatures below 0°C) in suspension, allowing them to crystallize around an impurity, such as dust or a grain of pollen. This initial nucleus, called an embryo, is the starting point for the formation of the hailstone.
The hailstones grow by crossing the different layers of the cloud several times, propelled by ascending currents. Each pass adds a new layer of ice, and the composition of these layers depends on the conditions encountered.
- Wet growth: When liquid water slowly freezes on the surface, it forms clear, dense layers.
- Dry Growth: During a rapid freeze, small air bubbles are trapped, creating opaque, less dense layers.
This alternation gives the hailstones a unique internal structure, visible in section and allowing their formation history to be traced.
When the weight of the hailstone exceeds the force of the updrafts, it falls at high speed. Larger hailstones sometimes continue to grow as they descend, reaching impressive sizes before hitting the ground.
Scientific advances to decipher giant hailstones
To understand how the largest hailstones form, researchers use modern tools such as medical scanners.
In Catalonia, during the 2022 storm, researchers studied 12 cm hailstones. They analyzed them using X-ray tomography scans. These non-invasive techniques allow the internal structure to be examined in detail. They reveal information inaccessible with other methods.
Analyzes show a core that is often eccentric, surrounded by irregular layers. These irregularities reflect the unstable conditions in the cloud. These results help to better understand hailstone growth and storm dynamics.
The analyzes also help to improve weather models, making it possible to better anticipate conditions conducive to giant hailstones. Understanding their formation could also lead to more accurate warning systems, reducing risks to exposed populations.
The impacts of giant hailstones on the affected regions
Giant hailstones cause massive destruction. In Catalonia, the 2022 storm caused damage estimated at more than 6 million euros, in addition to causing one victim and dozens of injuries. In Bangladesh, the 1986 record cited by IFLScience tragically illustrates their lethal potential, with 92 deaths and destroyed infrastructure.
Some studies suggest that giant hailstones could become more common due to global warming. The increase in energy available in the atmosphere and the rise in temperatures favor the formation of intense storms, creating the ideal conditions for these phenomena.
With an unwavering passion for local news, Christopher leads our editorial team with integrity and dedication. With over 20 years’ experience, he is the backbone of Wouldsayso, ensuring that we stay true to our mission to inform.
