How to Express Hail Intensity—Modeling the Hailstone Size Distribution

The local intensity of hail can be expressed by a variety of variables, such as hail kinetic energy, maximum hailstone size, and radar reflectivity–driven algorithms. All of these variables are connected by the hailstone size distribution. In the United States, the Community Collaborative Rain, Hail...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied meteorology and climatology 2019-10, Vol.58 (10), p.2329-2345
Main Authors: Grieser, Juergen, Hill, Marc
Format: Article
Language:English
Subjects:
Algorithms
Energy
Hail
Hailstone size
Hailstones
Hailstorms
Insured losses
Kinetic energy
Probability theory
Radar
Radar reflectivity
Reflectance
Risk management
Size distribution
Vulnerability
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The local intensity of hail can be expressed by a variety of variables, such as hail kinetic energy, maximum hailstone size, and radar reflectivity–driven algorithms. All of these variables are connected by the hailstone size distribution. In the United States, the Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) provides more than 37 000 observations that describe the diameter of the smallest, average, and largest hailstone; duration of hail; and overall hailstone number density. We use these data and the assumption of an exponential hailstone size distribution aloft to model the rate of hailstones hitting the ground per unit area, time, and hailstone size bin during the passage of a hailstorm. We found that total hail kinetic energy is proportional to the diameter of the largest hailstone to a power of less than 2. To validate these results, we compared them with hailpad observations of the largest hailstone diameters and hail kinetic energies in southwestern France. As an example application, we calculate the probability mass function for the largest hailstone observed by a hailpad given the largest hailstone occurring in its vicinity. We use this model at Risk Management Solutions, Ltd. (RMS), to calculate the vulnerability of subjects at risk as a function of the diameter of the largest hailstone.
ISSN:1558-8424
1558-8432
DOI:10.1175/JAMC-D-18-0334.1