How hail forms inside a storm- A Moment of Science

A Moment of Science

While many of us love to see snow in the Lowcountry, it’s far more common to see another type of ice falling from the skies- hail.

Every year it causes billions of dollars worth of damage to cars, property, and crops across the United States, most notably in “Hail Alley” out west where these balls of solid ice can be bigger than a baseball!

The largest hailstone ever measured in the US fell back in 2010 in Vivian, South Dakota. It measured 8″ in diameter and weighed nearly 2 lbs. Photo credit: NWS

Thankfully meteorologists can detect severe hail with radar and give you some warning, but how exactly does it form & grow? 

It begins with a storm. As it strengthens, so does its updraft, the vertical current of air through the storm. Raindrops are carried along for the ride high up within the cumulonimbus clouds into extremely cold areas of the atmosphere- freezing the once liquid rain into small pieces of ice. It will travel up and down through the storm, growing in size as more liquid water freezes on its surface.

Individual hailstones also can collide with one another inside the storm and grow exponentially- creating bigger chunks of ice made up of many smaller pieces of hail. But this increased size comes with increased weight. Eventually the hail stone becomes too heavy for the updraft to suspend it as gravity takes over and the ice plunges down to the ground.

Try this for yourself with a hairdryer and a ping pong ball-it’s a lot of fun!

Most of our hail in the Lowcountry isn’t that big, typically ranging from the size of a pebble to a quarter as our storm’s updrafts don’t stay too strong for too long to support hail growth. And, more importantly, our warm coastal climate melts a lot of the hail’s mass on the trip down.

Storm Team 2 Meteorologist David Dickson

Copyright 2021 Nexstar Media Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.


Join our daily newsletter!

Click for latest news and information

2021 Hurricane Ready Guide