Meteotsunami occurrences and causes in Lake Michigan

The occurrence of meteotsunamis in Lake Michigan is quantified at 10 locations from up to 20 years of historical water level records. Meteotsunami height data are fit with Pareto Type 1 and Generalized Pareto Distributions to estimate exceedance probabilities. The annual meteotsunami return level exceeds 0.25 m at all but two stations, with the largest annual return level of 0.62 m at Calumet Harbor. Analysis of radar imagery indicates that Lake Michigan meteotsunamis are associated primarily with convective storm structures, with a considerable contribution from frontal storms as well. Meteotsunami association with convective storm structures is more prevalent in southern Lake Michigan while frontal storm structures have a greater association with meteotsunamis in northern Lake Michigan. Water depths in southern Lake Michigan are conducive to Proudman resonance with convective storms while the northern Lake Michigan is too deep to meet Proudman resonance criteria, suggesting Greenspan edge wave resonance as the likely generation mechanism. Interestingly, meteotsunami events occur primarily in the late spring and early summer, approximately 1 month before the peak convective storm season but after the peak cyclone season. Overall, this statistical analysis provides valuable insight into the spatial and temporal trends in meteotsunami occurrence in Lake Michigan needed to estimate the risk posed by these dangerous coastal hazards. Key Points: Water level records indicate that meteotsunamis occur throughout the Lake Michigan basin Pareto family distributions describe size‐frequency character of meteotsunamis Convective and frontal systems are the primary meteorological cause of Lake Michigan meteotsunamis