Would “Tornado-Preventing” Walls Work?

Abstract

Simulations were performed using the Weather Research and Forecasting model in order to evaluate a proposal that called for the construction of three east–west “great walls” in the American Midwest to eliminate the major threat of tornadoes in Tornado Alley. The results of three simulations using the 31 May 2013 tornado outbreak are presented—one with natural terrain, one with 300-m tall walls as proposed, and another with walls much taller than proposed (2500 m). Through comparisons of temperature, moisture, instability, and supercell and tornado composite forecasting parameters, the “tornado-preventing” walls, as proposed, are shown to have very little impact on the atmosphere. When the height of the walls is greatly increased, the location of convective storms shifts eastward, instead of being eliminated. The short-term impacts of the taller walls imply possible desertification and areas with increased probability of non-supercellular tornadoes near the edges of the walls.