Hail Field Study

IBHS is conducting a multi-year, major field research effort to study hailstorms with the goal of reducing property losses, and improving weather forecast models and radar detection of hail. As part of this effort, IBHS is studying hailstorms in the Central Plains region in an attempt to better understand the characteristics of damaging hail, which depends on size, shape, density and hardness of hailstones.

This initiative began in 2012, when IBHS conducted a pilot study to determine the feasibility of collecting measurements of real hailstones; that study was the first known attempt to measure the hardness or compressive strength of natural hailstones.

To arrange an interview with IBHS, contact Brent Henzi at 850-879-0156, bhenzi@ibhs.org.

Objectives of the field study include:

  • Deploying a ruggedized, unmanned disdrometer (impact probe) to measure the hail size distribution and impact energy of falling hailstones.
  • Expanding 3D laser scanning of hailstones to collect 3D digital models of hail used to create molds and artificial stones at the IBHS Research Center. 3D scans will also help determine how hailstone strength and density are related.
  • Continuing collaboration with Penn State University to improve radar detection of hail, and initiating a new collaboration with the University of Oklahoma using mobile Doppler radars.
  • Evaluating the performance of new, experimental dual-polarization radar hail size algorithms.
  • Validating storm-scale hail simulation models.

The study is led by IBHS Lead Research Meteorologist Dr. Ian Giammanco, who serves as field coordinator for the project, and IBHS Lead Research Engineer Dr. Tanya Brown, a meteorologist who serves as logistics coordinator. Penn State Assistant Professor of Meteorology, Dr. Matt Kumjian, also collaborates with IBHS to improve hail detection, forecasting, and modeling capabilities.

IBHS Hail Field Research Timeline

WEATHER WHYS with Dr. Jon Nese (Penn State Department ofMeteorology)

The field study provides valuable data and insights for shaping ongoing work at the IBHS Research Center. IBHS evaluates the characteristics of natural hailstones in order to accurately manufacture artificial hailstones at the IBHS Research Center. Previous IBHS field study data were used when IBHS recreated a full-scale indoor hailstorm at the IBHS Research Center in February 2013.


2018 IBHS Hail Field Study Summary

IBHS Hail Field Study – Cullman, AL Record Hailstone

The Weather Channel – 2017 IBHS Hail Field Study

Part 1 – IBHS Hail Field Study Impact Disdrometer Overview (Facebook LIVE)

Part 2 – IBHS Hail Field Study Impact Disdrometer Overview (Facebook LIVE)

Part 3 – IBHS Hail Field Study Impact Disdrometer Overview (Facebook LIVE)

Tools of the IBHS Hail Field Study (Facebook LIVE)


Impact Disdrometer

3D Scanner

IBHS Hail Study Hailstone Collection (2016)

IBHS Hail Field Project Highlights – 2014

IBHS Hail Field Project Highlights – 2013

Calibrating Hail Impact Disdrometers


Oklahoma – Part 1

Oklahoma – Part 2

Impact Disdrometers

Research Reports & Summaries

The Impact of Vertical Wind Shear on Hail Growth in Simulated Supercell Storms

The rapid advancement in high-performance computing has opened the door to new research into hailstorms through simulations of individual thunderstorms and their internal processes. As a result of this research, IBHS member companies have the opportunity to leverage new strategies for hail forecasting and more accurately simulating potential loss scenarios. The following research summary provides a brief synopsis.

Research to Operations: A Hail Detection Network

In 2014, scientists and engineers at the IBHS Research Center began investigating in-situ measurement strategies to detect and sample hail within a thunderstorm. The need was for a deployable or fixed platform capable of sensing hail size and kinetic energy distributions while also withstanding large hail impacts. The emergence of low-cost, open-source microcontrollers, sensor packages, and developer environments has opened the door to more cost-effective and rugged solutions. This paper highlights the development and successful pilot testing of hail impact disdrometer prototypes in 2014 and the construction of a fleet of six rapidly deployable impact disdrometer probes.

2014 IBHS Hail Field Research Summary

2014 marked the third year of IBHS’ field program to measure characteristics of hailstones. The program began in 2012 as an effort to understand the characteristics of natural hailstones for use in laboratory production of hailstones. These data are vital to creating realistic hail that can be used in laboratory studies looking at the response of building materials and systems to hail impacts. Additionally, deployments have been designed to provide ground truth data to improve radar algorithms used for detecting and mapping of hail impact areas. Improved mapping of hail impact areas and the characterization of hail sizes within those areas are vital to understanding exposure, risk, and loss mitigation strategies.

2013 IBHS Hail Field Research Summary

In 2013, data on 685 stones from 12 parent thunderstorms were collected. Several high spatial resolution cases were collected with approximately 1 to 2 mile spacing between data collection points across the width of the hail swath, and two of these cases are described in detail. Comparisons of laboratory and field hailstone measurements are discussed. A new instrumentation platform, the IBHS photogrammetric Camera Probe, was also introduced, and enabled investigations into the frequency and spatial distributions of hailfall at a particular location. The imagery collected by the Camera Probe proved useful in determining the timing of hailfall when compared to the radar indications.

2012 IBHS Hail Field Research Summary

In 2012, IBHS conducted a pilot study to determine the feasibility of collecting measurements on real hailstones.  That study measured 239 hailstones from nine parent thunderstorms, and was the first known attempt to measure the hardness or compressive strength of natural hailstones.

Improving the Science of Hail Verification

Every spring, IBHS researchers traverse the plains to learn more about the dynamics of hail. In May, 2016, we responded to a severe hailstorm in Dalhart, TX. As soon as it was safe to do so, IBHS researchers fanned out across the area to collect, analyze and scan hailstones. We then collaborated with CoreLogic which used IBHS’ ground truth data to test and verify the hail algorithm CoreLogic developed to validate specific weather events. Until recently, insurers would wait for policyholders to notify them of damage after a hailstorm, this delay impedes the insurance process. Innovations developed by CoreLogic in hail verification allows insurers to prioritize and validate claims and respond to events strategically. IBHS is proud to be working with CoreLogic and looks forward to continuing to provide data as we develop a better understanding of hail and look for ways to reduce property losses.

Want to learn more? Check out the joint IBHS/CoreLogic report Improving the Science of Hail Verification at http://bit.ly/2n7yJNv

American Meteorological Society Journal of Atmospheric and Oceanic Technology

Using 3D Laser Scanning Technology to Create Digital Models of Hailstones (July 2017 Bulletin)

Evaluating the Hardness Characteristics of Hail through Compressive Strength Measurements

Evaluating Hail Damage Using Property Insurance Claims Data


Research Partners