Hailstones are not spheres – they’re shaped more like a rugby ball

By David Hambling

A team of storm chasers spent years tracking down terrible weather across the US to establish this simple fact: hailstones aren’t round. They have more complex shapes than previously thought and this knowledge could help meteorologists understand their formation and better predict the dynamics of hailstorms on weather radar.

“It’s along the same lines as ‘no two snowflakes are alike’ – we can say the same thing about hailstones,” says Matthew Kumjian at Pennsylvania State University.

He and his colleagues carried out a hailstone survey over the course of …