National Weather Service Weather Forecast Office

South Dakota Storm Produces Record Hailstone

NOAA’s National Climate Extremes Committee, responsible for validating national weather records, has declared a hailstone found last week in Vivian, S.D., to be the largest in diameter and heaviest ever recovered in the United States.

Found after a July 23, 2010, severe thunderstorm by Vivian resident Les Scott, the hailstone is 8.0 inches in diameter and weighs 1.9375 pounds (1 pound, 15 ounces) with a circumference of 18.62 inches.

These measurements displace the previous hailstone record for weight, previously 1.67 pounds for a stone in Coffeyville, Kan., in 1970. They also surpass 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. 

            “I’m just glad nobody got hurt and hope the town will recover soon,” Scott said.

            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. “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.”

            After getting Hintz’ notice of a possible record hailstone, personnel at National Weather Service Central Region headquarters in Kansas City, Mo., requested activation of the National Climatic Extremes Committee to examine and judge Scott’s hailstone. Personnel from the Aberdeen office traveled to Vivian to measure and weigh the hailstone, and then turned their findings over to the three-person committee. After a thorough review of the facts, committee members certified its record-breaking status.

            More information can be found on the Aberdeen, SD National Weather Service website at http://www.crh.noaa.gov/abr/?n=stormdamagetemplate.

            Information about the National Climatic Extremes Committee and existing weather records may be found at http://www.ncdc.noaa.gov/extremes/ncec.

            NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources. Visit http://www.noaa.gov.