Record Hailstone Falls in Vivian, South Dakota

Posted on August 1, 2010

NOAA's National Climate Extremes Committee, the agency responsible for validating national weather records, has declared a hailstone found last week in Vivian, South Dakota, to be the largest in diameter and heaviest ever recovered in the United States. The hailstone is 8.0 inches in diameter and weighs 1.9375 pounds (1 pound, 15 ounces) with a circumference of 18.62 inches.

The hailstone was found by Vivian resident Les Scott after a severe thunderstorm on July 23, 2010.

The hailstone surpasses the previous hailstone record for weight, previously 1.67 pounds for a stone in Coffeyville, Kan., in 1970. It also surpasses the record for diameter, which was 7 inches for a hailstone found in Aurora, Neb., in 2003. The Aurora hailstone still holds the record for circumference of 18.75 inches.

NOAA says the updraft strength in the supercell that created the monster hail likely ranged from 160-180 mph.This image shows a hole the hailstone made in a Vivian resident's deck.

David Hintz, warning coordination meteorologist at NOAA's Aberdeen weather forecast office said a local power outage likely led to the hailstone melting some before it could be measured. Hintz said, "Mr. Scott told me the area was littered with large hailstones and the largest had a greater diameter when he first found it. He immediately stored it and several others in his freezer, but a power outage caused some melting."

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