Ten Things You Should Know About Hail, Colorado's Most Damaging Weather Phenomenon

Hail is like the mosquito of precipitation: a damn nuisance with absolutely no redeeming qualities. Fog is nicely moody; so is rain, and petrichor is one of the best scents ever. Snow holds the promise of forts and friendly fights and rotund men with sticks for arms and carrot noses. Even sleet can glass over an entire landscape, and while you might get stuck in your house for a bit, outside it’s an icy wonderland of shining freeze.

But hail? Hail just sucks.

Just ask the folks who got stuck out at Red Rocks last night, pelted by golf-ball-sized hail that sent some people to the hospital. Or the owners of cars or gardens or trees that were out in the elements and suffered the after-effects of the shotgun-scattershot weather. And no metro Denver homeowner is going to get through today without thinking about their roof...especially with more hail predicted.
Since we’re all bound to be thinking and talking about hail today, here are a few hail-related facts that you can share with your fellow victims — er, Coloradans.

Hail is really about wind

A thunderstorm is required for for a real hailstorm, one with strong upward winds. Those updrafts push rain back up into the atmosphere, where it freezes and then falls again. This cycles until the pellets of moisture become too heavy for the wind to buoy up again, and it falls as hail.

Hail happens everywhere

Given the above conditions, hail is created during thunderstorms all over the country. But if conditions aren’t right — mainly, it’s not cold enough for the gathered moisture to remain solid as it falls — you won't be pummeled by hail, just soaked by rain.

The size of the hail depends on the strength of the updraft

Based on the above metrics, it makes sense that the stronger the wind, the heavier (and larger) the hail will remain in that rising and falling cycle in the upper atmosphere — resulting in larger hail hitting the ground. (And your car, house and possibly children.)

While tornados get better press, serious hailstorms are worse

There are books and movies and songs (oh, my!) about tornadoes, and nothing much about hail. But serious hailstorms are five times more common and cause far more damage in terms of recovery costs. Across North America, the destruction caused by hail costs over $10 billion and accounts for nearly 70 percent of property-damage claims attributed to weather.

The largest hailstone recorded fell in South Dakota in a 2010 storm

The largest known hailstone weighed almost two pounds and had a diameter of about eight inches, according to a report from the National Climatic Data Center; that’s the size of a regulation volleyball. And as with any hailstone measurements, experts presume that it was significantly larger on impact than it was by the time it could be measured and recorded.

Denver is smack in the middle of Hail Alley

It’s not your imagination that Denver — and Colorado in general — gets more than its share of hail. It’s in a swath of the western U.S. called Hail Alley that stretches from Wyoming down to Texas and Colorado over to Kansas, including the western half of the Dakotas, most of Nebraska and Oklahoma, and parts of Missouri, Iowa and Illinois. Colorado specifically is so inclined to hail because of its elevation: On the high plains, there’s simply less space between the atmosphere and the ground for hail to have the chance to melt away. (Thanks, Rocky Mountains.)

Oklahoma carries the dubious distinction of having the worst hail seasons

The Sooner State has had over 2,200 serious hail events — a storm that includes hailstones measuring over one inch — since 2015. That's a lot of dent repair.

The costliest Denver hailstorm (to date) was in May 2017

That storm caused $2.3 billion in damage — and those were only the losses claimed by insurance. How this year’s hailstorms will measure up is still in question.

A 2018 hailstorm killed two animals and injured fourteen people at Cheyenne Mountain Zoo in Colorado Springs

A severe hailstorm pelted the Cheyenne Mountain Zoo in 2018, killing a four-year-old muscovy duck named Daisy, and Motswari, a thirteen-year-old cape vulture. Sixteen other animals were injured, along with fourteen visitors, some of whom had head injuries and broken bones — like the victims at Red Rocks last night.

Hail is getting worse

By the end of this century — which might feel like an eternity, but we’re almost a quarter of the way there —scientists publishing with the American Meteorological Society project that our region will experience three more serious hail events each year, with the greatest impact seen across the northeastern plains. So cover your vehicles, make sure your insurance is paid up, and watch the skies, Colorado.