Using the ERA5 Reanalysis Dataset to Identify Extreme Flooding Events in the Northeastern United States

This study evaluates the utility of the ERA5 dataset in assessing extreme flooding events in the Northeastern United States. The ERA5 is a new global climate reanalysis dataset from ECMWF that spans 2010-01-01 through 2016-12-31, with the years back to 1979 currently in production. The ERA5 dataset has a spatial resolution of 31 km, and an hourly temporal resolution. Data included in this study is over the region from 37.5°N to 50°N, and 82.5°W to 65°W, encompassing the Northeast US. We first quantify precipitation spin-up as the model equilibrates to the initial conditions: spin-up of precipitation is about 20% in the first 12 hours. In addition, this study explores the ability to simulate floods in the Lake Champlain Basin using extreme precipitation and other variables from ERA5. Emphasis in the case study will be given to verifying the spatial and temporal distribution of precipitation over the duration of an event, as well as a discussion of the land-atmosphere interactions and their role in the intensity of the flood.