A comparison of wind speed and forest damage associated with tornadoes in Northern Arizona

Abstract

Damage surveys in the aftermath of tornadoes occurring in the forested regions of the Mogollon Rim in northern Arizona have been assessed using the enhanced Fujita scale (EF scale) damage indicator (DI) and degree of damage (DOD) tables. These surveys often revealed different DODs within close proximity as well as different spatial patterns and areal extent of tree damage exhibiting the same DOD, making the determination of wind speed and EF-scale ratings challenging. A localized tornado outbreak occurred across northern Arizona on 6 October 2010, producing at least 11 tornadoes and substantial areas of forest damage. Remarkably, one of these tornadoes passed over a three-dimensional sonic anemometer. Wind data from this sensor are compared with tree damage in the adjacent forest to assess the performance of the EF-scale metrics for damage to trees.