Understanding the 2013 Boulder Flood: Assessing Extreme Precipitation Events and Future Climates in the Community Earth System Model (CESM)
Probability distribution functions (PDFs) were calculated for daily values of observational and reanalysis variables: precipitation, precipitable water, and low-level winds. Each of the PDFs were compared with equivalent variables in the CESM simulations and analyzed over three regions of different areal extent occupying the eastern Rocky Mountains. The PDF calculations were found to be sensitive to the choice of the spatial region with fewer high precipitable water events in the northern domain and a greater number of high precipitable water events in the more southerly domain. The similarities between observational and present-day CESM PDFs enabled us to study changes to PDF distributions in future climate simulations. They predict a significant increase in precipitable water over the Boulder flood region. Given the importance of high precipitable water in the 2013 Boulder flood precipitation event, the potential for more frequent and stronger flooding events is significant.