Hail Pad Damage

July 28, 2005


Referred by: Noah Newman
Summary authors & editors: Noah Newman

Is this a picture of our crater-ridden moon? It's actually a picture of a “hail pad.” The hailstones (traveling up to 80 miles per hour or 128 km per hour) that made these “craters” can cause serious damage to property and pose potential danger to animals and humans alike. Our knowledge of hail is limited because it tends to occur over small areas for short periods of time. So far, more than 2,000 back yard weather buffs of all ages and backgrounds are volunteering their efforts to observe and study rain, hail, and snow in six states. CoCoRaHS, the Community Collaborative Rain, Hail and Snow Network is a unique, non-profit, community-based network of volunteers reporting simple, yet important data. One of the prime motivations for collecting hail data is to gather better information on the frequency, timing, and characteristics of hail storms and the hailstones that accompany them. To collect hail observations, CoCoRaHS participants use a 1-in thick Styrofoam pad covered with heavy duty aluminum foil to measure the number and size of hailstones. After a hailstorm, damaged hail pads are collected from volunteers. Student interns examine each hail pad to measure and count the size and number of dents and relate dent size to actual hailstone size. This data is then analyzed by scientists at Colorado State University. CoCoRaHS on-line hail reports are sent directly to the National Weather Service, which often results in the issuing of severe thunderstorm warnings. Henry Reges (a coordinator for CoCoRaHS) helped with this summary.

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