Collaborative Research: RAPID--Multi-Scale Investigation into the Storm Processes of the 10 August 2020 Midwest Derecho

University Of Oklahoma Norman Campus, Norman OK

Investigators

Abstract

On 10 August 2020, a particularly intense derecho produced widespread high-wind damage from eastern Nebraska through northern Indiana, resulting in 3.8 billion USD in estimated agricultural losses in Iowa. Derechos, or long-lived windstorms produced by mesoscale convective systems (MCSs), remain an important atmospheric phenomenon to understand because they produce large-scale wind damage areas, varying from 20 – 200 km in width to hundreds of kilometers long. This award will allow a multidisciplinary scientific team (i.e., atmospheric scientists, remote sensing experts, wind and structural engineers) to perform high-resolution numerical simulations and detailed damage surveys across multiple spatial scales to investigate storm processes in derechos. Relating detailed documentation of high-wind damage with storm processes can provide vital information on extreme wind production in derechos and storm damage potential, leading to improved understanding of severe-storm processes, radar interpretation, and risk communication associated with warnings to the general public. Storm characteristics and near-surface wind flow of 10 August 2020 derecho will be investigated through 1) high-resolution simulations of the event using a state-of-the-art numerical modeling system as a proxy for the real event, and 2) detailed comparisons of radar signatures to damage information provided by 2D and 3D analyses of unpiloted aerial systems (UAS) data, satellite imagery, and ground truth surveys. Simulations that best depict the evolution of the derecho will be analyzed to explore the mechanisms responsible for the unique physical characteristics of this event that were responsible for the extreme wind production. The large-scale character of the damaging winds over vegetation and crops susceptible to long-term damage and passage of the derecho’s core close to Des Moines and Davenport National Weather Service radars in Iowa provide a unique opportunity to better connect damage information to velocity structures sampled by radar. The detailed analysis of wind damage produced in this study will provide an unprecedented validation dataset for the high-resolution numerical simulations. This unusually comprehensive dataset will be used to understand the physical processes responsible for extreme wind damage. Additionally, detailed damage documentation can also be used to calibrate satellite-based assessments in future high-wind events and could enable the development of additional damage descriptors based to vegetation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.