A simple vortex model of a thunderstorm downburst – a parametric evaluation

Thunderstorm downbursts are short-lived, transient extreme wind events which can cause wind speeds equivalent to a category EF3 tornado (~150mph). The complex flow field which they produce has previously been the subject of time-expensive numerical modelling. However, it is well-known that there is a large, random variation in full-scale downbursts and so a quick, easily varied model would be of benefit to engineers calculating dynamic loading on structures. This paper introduces a simple and computationally inexpensive vortex model of a downburst, which is shown to model the main features of the flow field in a physically simulated thunderstorm downburst to an appropriate degree of accuracy.