NCEI’s State Climate Extremes Committee functions as a sort of “CSI: Meteorology,” probing claims of state records and issuing investigative reports. Here’s the story of a hailstone found by Craig Mann in Alabama on 3/19/18. @NWS @disastersafety #ALwx 1/6

First on the scene at Craig Mann’s house in Walter, AL, were officials from @NWSHuntsville, who used a tape measure and a scale to record its size. @NWS 2/6

The Insurance Institute for Business & Home Safety—a group that has a vested interest in understanding hail and the damage it causes—then visited and conducted a laser scan of the stone. @disastersafety 3/6

The measurements suggested a record stone, so the SCEC was convened. It judged the stone to be “meteorologically plausible,” given radar imagery showing a supercell storm (L, white dot marks Mann’s home) and photos of severe hail damage. 4/6

SCEC ruled the hailstone set the #ALwx record in diameter (5.38 in.), weight (9.8 oz.), volume (19.80 http://cu.in .), and circumference (13.75 in.). It was the first time measurements from a laser scan were used to establish an SCEC determination. @disastersafety 5/6