Each spring, IBHS deploys a team to study hailstorms in the Central Plains region to better understand the characteristics of damaging hail (size, shape, density and hardness). This provides valuable data and insights for shaping ongoing work at the IBHS Research Center focused on reducing property losses.
IBHS announced the documentation of what is believed to be the largest hailstone ever to have fallen in Alabama, and one of the three largest ever documented east of the Mississippi river. At 5⅜ inches (13.665 cm) at its largest measurement and approximately 0.6125 or ⅝ of a pound, its total volume was approximately 20 cubic inches. The hailstone fell during a severe storm on March 19 in Cullman, Alabama. Photos of the hailstones, the documentation, and damages are available here.
The IBHS team traveled throughout the Central Plains and collected measurements on falling hailstones from 60 different storms, increasing data collected and number of hailstones 3D scanned.
Using 3D Laser Scanning Technology to Create Digital Models of Hailstones (July 2017 Bulletin)
The field team used a 3D scanner to collect 3D digital models of natural hailstones that were later used to create molds and artificial stones at the Research Center. Scans were also used to study how hailstone strength and density are related. IBHS continued its collaboration with Penn State University to improve radar detection of hail, and initiated a new collaboration with the University of Oklahoma using mobile Doppler radars.
The field team deployed its first network of impact disdrometers to measure the hail size distribution and impact energy of falling hailstones, published its first paper on hailstone strength, initiated collaboration with Texas Tech University, began collaboration with Nationwide Insurance using hail measurement kits, and scanned its first hailstone using a 3D scanner. Researchers at the Research Center built a new hail machine capable of creating 1,000 hailstones per day to precise specifications.
Evaluating Hail Damage Using Property Insurance Claims Data
Evaluating the Hardness Characteristics of Hail through Compressive Strength Measurements (American Meteorological Society Journal of Atmospheric and Oceanic Technology)
The field team collected data on 1,636 hailstones, initiated an ongoing collaboration with Penn State University, published a paper with the National Center for Atmospheric Research (NCAR) on hail aerodynamics, and deployed impact disdrometer prototypes.
Characteristics of Severe Hail Field Research Summary 2014
The field team collected data on 658 hailstones, initiated research collaboration with State Farm Insurance, and used hail strength data to improve impact tests at the IBHS Research Center. Field study data was used to recreate a full-scale indoor hailstorm at the Research Center.
Characteristics of Severe Hail Field Research Summary 2013
The pilot study was the first known attempt to measure the hardness or compressive strength of natural hailstones. The field team collected data on 239 hailstones using a compressive force device developed by IBHS.