Hail: One of the Most Costly and Destructive Severe Weather Impacts

It has been a rough spring season across much of the central and southern U.S., thanks to an onslaught of severe storms. While it is typically tornadoes that grab all of the headlines, hail can be just as destructive and costly. Here is what you need to know about hail as the severe weather season marches on.

How Hail Forms

Just like rain and snow, hail is also a form of precipitation. What distinguishes hail from other types of precipitation is that it is composed of solid ice. Despite the similar appearance, hail is not the same as freezing rain. The difference is that freezing rain comes down from the sky as liquid water and freezes when it reaches the ground. Conversely, hail falls as a solid type of precipitation.

Hailstones form during thunderstorms. The rain is carried upwards by rising air known as an updraft. Once the moisture reaches the higher levels of the atmosphere, it finds colder air that turns into frozen moisture droplets. The hailstones grow as the frozen moisture droplets clash with the surrounding water vapor. This collision sets off a reaction in which the water freezes on the surface of the hailstone, forming several layers of ice.

Stronger thunderstorms inherently translate to larger hailstones. This is because more powerful storms have stronger updrafts. This strength allows the hailstone to continue to float within the cloud by the updraft for a longer period of time, keeping it going through the cycle of colliding with more droplets and adding to the volume.

The hailstone finally makes its way to the ground when gravity overtakes the power of the updraft, resulting in what people recognize as hail.

How Meteorologists Estimate Hail Size