Nine-Inch Hail? Potential World-Record Hailstone Identified in Argentine Research Project

The Córdoba province of Argentina was battered by massive hailstones on Feb. 8, 2018, some of which were so large they left divots in the ground after plunging from the sky. The slideshow above shows some examples of the huge hailstones and divots from that day.

One of those hailstones, that fell in the town Villa Carlos Paz, might have set a new world record for size based on an analysis of video in a study led by Matthew R. Kumjian and Rachel Gutierrez of the Department of Meteorology and Atmospheric Science at Pennsylvania State University.

The hailstone was estimated to have a maximum dimension between 7.4 and 9.3 inches. That would rival the worldwide record for the largest hailstone, which had a maximum dimension of 8 inches after it fell from a storm in Vivian, South Dakota, on July 23, 2010.

The northern region of Argentina where this hailstorm occurred has a reputation for spawning supercell thunderstorms with large hail and tornadoes, similar to South Dakota in the U.S. Great Plains.

In the video clip below, you can see this particular hailstone bounce off an awning in the upper right before landing in the street beginning around 11 seconds. The video then zooms in closer on the hailstone as it lays in the street about 14 to 15 seconds into the clip.

Since the photogrammetrically estimated hailstone was never collected and preserved in a freezer, we will never know its official measured size.

Another hailstone in the Villa Carlos Paz storm was measured to have a maximum dimension of nearly 7.1 inches (18 centimeters). The authors of the study said that, to their knowledge, this hailstone is the largest officially measured in the Southern Hemisphere.

The researchers also proposed a new category of hail size called "gargantuan" for any hailstones with a maximum dimension of 6 inches or larger (15 centimeters), or the size of a honeydew melon. The term "giant hail" is currently used to describe any hailstones with a maximum dimension of 4 inches or larger, which is about the size of a softball.

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