The Spatial and Temporal Characteristics of Atmospheric Conditions during the 2013 Colorado Floods

We investigate the atmospheric conditions that resulted in the 2013 Colorado floods, which caused 8 deaths and $2 billion in property damages. We assess the spatial characteristics of the rainfall event by using object identification and clustering methods and by using Poisson clustering techniques for the temporal characteristics. The characteristics of the atmospheric moisture and rainfall that led to this flooding event are found using satellite imagery, station and reanalysis data, allowing us to assess the frequency of these characteristics and any associated trends in the recent past. We also quantify the sources of moisture during the 2013 flood, and hypothesize that the amount of moisture from local moisture recycling is larger than from the Southwest US Monsoon and the Gulf of Mexico due to antecedent wet soils and record high temperatures. The observed hydrologic record is used to assess if extreme runoff events had occurred under similar meteorological conditions and if antecedent conditions and the sources of moisture are similar for other extreme hydrologic conditions. The findings of this study will allow us to understand the spatial and temporal features of atmospheric conditions that lead to hydroclimatic extreme events in the region, and aid in informing both climate and hydrologic models to more accurately simulate hydroclimatic extremes.