Reclamation Information Sharing Environment (RISE)

In this study, we aim to improve understanding of heavy snowfall events across the Western United States by exploring the following three components of analysis. The first component includes describing historical snowfall events using point observations from the SNOTEL dataset in six Reclamation headwater basins. The second component involves characterizing weather types (e.g., atmospheric forcing) associated with the top eight heaviest historical snowfall events in each basin using the European Center for Mid-range Weather Forecasting’s (ECMWF’s) ERA-Interim reanalysis dataset (Dee et al. 2011) combined with the weather typing algorithm of Prein and Mearns (2021). The final component entails exploring simulation of historical weather types in climate projections from the Community Earth System Model version 2 (CESM2, Rodgers et al. 2021) Large Ensemble 2 dataset (LENS2). We focus on six Reclamation watersheds located in headwater regions, which include the Methow basin, WA, the Sun River basin, MT, the Upper Snake River basin, ID/WY, the Upper Klamath Lake basin, OR/CA, the Truckee-Carson basins, CA/NV, and the Upper San Juan basin, UT/AZ/CO/NM.