Overview

VDE Americas provides hail return interval data covering the Continental United States (CONUS). The hail return interval metric characterizes the estimated amount of time between discrete severe weather events based on hailstone diameter. This set of data includes the return interval in years for naturally occurring hail—ranging in diameter from 25 mm (1 in.) to 95 mm (3.7 in.)—and the maximum estimated hailstone diameter for cumulative return interval periods. The return interval periods for this data set include <25 years, 25–50 years, 50–100 years, 100–250 years, 250–500 years, 500–1,000 years, 1,000–5,000 years, and >5,000 years.

Developed in partnership with Dr. John Allen of the Allen Research Group, VDE Americas’ meteorological model combines calibrated Next-Generation Radar (NEXRAD) data with observed hail records maintained by the NOAA Storm Prediction Center. The resulting geospatial meteorological hail risk data sets are visualized as contour maps. These hail return interval data are especially useful for characterizing the maximum expected hailstone diameter over an asset's operational lifetime. For example, VDE Americas uses naturally occurring hail return interval data to inform engineered probable maximum loss (PML) and average annual loss (AAL) estimates for utility-scale solar farms to inform site selection, product procurement, hail mitigation strategies, and insurance pricing and terms.

VDE Americas’ hail return interval data can help insurers, risk advisors, technical advisory firms, and other service providers understand location-specific hail risk, which affects agriculture (crops and livestock), transportation (car dealerships), and the built environment (homes, businesses, and civic facilities) throughout the CONUS.  By identifying and characterizing hail risk, stakeholders can take steps to mitigate specific perils or properly price potential insurability concerns during the planning process. 

When all hail breaks loose—have a plan.