Improved characterization of damage patterns from idealized tornado models

Tornadoes have caused significant damage and casualties in the past decades. These losses have spurred efforts toward tornado-based design in codes and standards, which requires rigorous estimates of wind characteristics and wind-induced loading of tornadoes. Due to the difficulty of obtaining in-situ measurements of tornadic near-surface wind speeds, a promising method of estimating near-surface wind speed based upon the damage inflicted is developed. The method includes fall directions of trees and crops in residential and agricultural areas that exhibit distinct fall patterns. The observed fall patterns are used to estimate parameters of the Rankine vortex model and reproduce the near-surface wind field. The wind field then can compared with wind speed based on structural damage.