Projecting End-of-Century Human Exposure from Tornadoes and Severe Hailstorms in Eastern Colorado: Meteorological and Population Perspectives

Abstract

AbstractSevere convective storms along the Front Range and eastern plains of Colorado frequently produce tornadoes and hail, leading to substantial damage and crop losses annually. Determination of future human exposure from these events must consider both changes in meteorological conditions and population dynamics. Projections of EF0 + tornadoes (on the enhanced Fujita scale) and severe [1.0+ in. (25.4+ mm)] hail reports out to the year 2100 are computed using convective parameter proxies generated from dynamically downscaled GFDL Climate Model, version 3 (GFDL CM3), output by the WRF Model for control and future climate scenarios. The proxies suggest that tornado and hail days in the region may increase by up to one tornado day and three hail days per year by 2100, with the greatest increases across northeastern Colorado. Using a spatially explicit Monte Carlo model, projected future frequency and spatial changes in tornadoes and hail are superimposed with population projections from the shared socioeconomic pathways (SSPs) to provide a range of possible scenarios for end-of-century human exposure to tornadoes and hailstorms. Changes in hazard frequency and spatial distribution may amplify human exposure up to 117% for tornadoes and 178% for hail in the region by 2100, although specific results are sensitive to uncertain combinations of future overlaps between hazard spatial distribution and population. Findings presented herein not only will provide the public, insurers, policy makers, land-use planners, and researchers with estimates of potential future tornado and hail impacts in the Front Range region, they also will allow the weather enterprise to better understand, prepare for, and communicate tornado and hail risk to eastern Colorado communities.