Falling hail can reach deadly speeds -- up to 100 mph, says National Weather Service

Chunks of ice falling from the sky is never a good thing, but the National Weather Service released data Wednesday proving it can also be deadly.

“How fast does hail fall?” asked the National Weather Service on Facebook. “One estimate is that a small hailstone roughly 1/2 inch in diameter falls at about 20 mph ... while baseball- to softball-sized stones can reach speeds near a major league fastball -- 100 mph.”

The post was accompanied by an image of a National Oceanic and Atmospheric Administration vehicle with its windshield busted and countless dents in the hood.

“Hail can damage aircraft, homes and cars, and can be deadly to livestock and people,” says the National Severe Storms Laboratory.

NWS officials say the biggest hailstone on record in the U.S. was 8 inches in diameter and weighed one pound and 15 ounces. The National Severe Storms Laboratory says it fell in June 2010 in Vivian, South Dakota, a community of about 120 people.

Hail is formed when thunderstorm updrafts “carry raindrops upward into extreme cold areas of the atmosphere,” says the National Severe Storms Laboratory.

The resulting ice balls eventually get too heavy for the updraft to carry and start raining down, says the lab’s “Hail Basics” page.

“The stronger the updraft the larger the hailstone can grow,” says the site.

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