Quantification of mechanisms for damaging wind generation in simulated derecho events

Damaging winds generated by non-tornadic thunderstorms are responsible for property and crop losses comparable to or greater than tornadoes. The number of annual severe-thunderstorm wind reports exceeds the number of annual tornado reports by at least an order of magnitude, yet tornadoes have been the focus of much of the research in the U.S. Four separate derecho events, each representing a different meteorological environment, geographic location, and season, were simulated with the Weather Research and Forecasting (WRF) model to investigate wind-generating mechanisms in the associated long-lasting, intense mesoscale convective systems (MCS). High-resolution model output was used to objectively identify severe and potentially damaging winds and their associated generating mechanisms. Rear-inflow jets (RIJs) were associated with the largest spatiotemporal impacts. They generated the most severe and potentially damaging winds in the derecho events, were attributed to the most observed reports, and tended to generate longer lasting winds. Downbursts (DBs) and Mesovortices (MVs) generated severe and potentially damaging winds less frequently and were attributed to fewer reports but produced stronger winds on average. The MV mechanism was the strongest solo mechanism, on average, and produced even stronger winds when combined with a RIJ or DB. These results suggest that RIJs likely generate most severe and/or damaging winds in derecho events but not the most intense winds, which are most likely to be generated by MV-related mechanisms.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Atmospheric Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Killion, Kyle Jarrard

Contributors dc:contributor

• Trapp, Robert J
• Lombardo, Franklin T
• Nesbitt, Stephen W

• Derecho
• Severe Weather
• Damaging Wind

Statement dc:rights

• Copyright 2024 Kyle Killion

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/124382

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F124382