All About Hail

March 31, 2020

What is hail?

Hail is a type of precipitation or water in the atmosphere that forms when water drops freeze together in the cold upper regions of thunderstorm clouds. A frozen water drop begins to fall from a cloud during a storm but is then lifted back into the cloud by a strong updraft of wind. When the hailstone lifts, it hits more liquid water drops, which then freeze to the hailstone, adding another layer to it. A hailstone eventually falls to the ground once it’s too heavy to remain in the cloud, or when the updraft stops or slows down.

These chunks of ice are called hailstones and are typically transparent (clear) or translucent (cloudy).

Hailstones differ from frozen rain – frozen rain falls to the ground as water and freezes as it approaches the earth. By contrast, hail falls to the ground, not as water, but as a solid.

Hailstones can cause extensive damage to residential and commercial property, vehicles, and even crops. To no surprise, scientists have tried ways to prevent hail. In the 18th century, Europeans fired cannons into clouds. In the 20th century, scientists in the United States and Russia tried cloud seeding, the process of adding chemical particles into clouds from rockets or aircraft to control rain and hail. Sadly, there is no evidence that any technique has been effective.

Where is hail?

Some parts of the world are more susceptible to hail than others, including India and China, and parts of the midwestern United States. In the United States and Canada, meteorologists refer to the Great Plains region as “Hail Alley.”

In 2010, South Dakota recorded the largest hailstone in the United States, measuring 8 inches in diameter, roughly the size of a volleyball. The world record for hailstone by weight was recorded in Bangladesh, India, in 1986 with a 2.25-pound monster.

Here in Colorado

Colorado’s hail season is classified as April 15 to September 15, with the most frequent and most destructive hailstorms in June. Hailstorms do occur many times in eastern Colorado each summer with hailstones frequently measuring 1 to 2 inches in diameter and falling at a rate of 80 miles per hour.

On August 13, 2019, the largest hailstone recorded in Colorado was found near Bethune, measuring 4.83 inches in diameter, which is roughly the size of a softball, and weighed more than a half-pound. The previous record in Colorado was 4.5 inches in diameter.