Meteorological Causes and Atmospheric Conditions Associated with Extreme Precipitation Events in Southeast Michigan

Flooding is a hydrological phenomenon influenced by extreme precipitation generating storms with destructive impacts on various sectors, including infrastructure. The objective of this study is to understand the meteorological causes of extreme precipitation, by studying historical cases that exceed geographically-varying thresholds, specifically percentile and number of grid points, using the ECMWF Reanalysis v5 (ERA5) precipitation in Southeast Michigan. Analyzing data from 1991-2023, we found that extreme precipitation dominantly occurs during the warm season (April to September). Furthermore, we categorized identified cases based on meteorological phenomena, including Fronts (FRT), Extratropical Cyclones (ETC), Tropical Cyclones (TC), and Mesoscale Convective Systems (MCS). To identify FRT and MCS, we employed the Thermal Front Parameter and the Python FLEXible object TRacKeR (PyFLEXTRKR) objective identification methods. Our preliminary results indicate that the primary mechanism responsible for extreme precipitation are FRTs, followed by ETCs, TCs and MCSs. In the future, we will evaluate how Global Climate Models (GCMs) represent the relative contribution of these events on precipitation in Southeast Michigan.