Increases in convective wind gusts from enhanced thermodynamically driven processes in a warmer climate

Convective wind gusts produced by downburst or cold pools can have devastating impacts on our infrastructure: buildings, powerlines, railways. Yet, how climate change affects convective wind gust is largely unexplored, with only very few publications. Despite this, changes in a number of thermodynamic processes point at potential increases in convective gusts. Heavier precipitation increases the liquid water loading of downdrafts, producing larger downward drag and greater potential of evaporation of rain and therefore stronger negative buoyancy. In addition, predicted decreases in boundary layer relative humidity increases boundary layer depth and evaporation of rain, and may also promote the occurrence of more organized convective systems. Here, we present results from a long convection-permitting model simulation showing a clear relationship between cold pool strength and maximum gust. In addition, we investigated a case of severe convection in our “Future Weather” system (repeating present-day weather events in warmer and colder climates using pseudo global warming). In these simulations we show a clear relation between the downward mass flux of air and the strength of the maximum wind gust.