What Gridded Snow Water Equivalent Dataset Should I Use?

Gridded snow water equivalent (SWE) datasets are critical for accurate and efficient runoff modeling. Snowmelt modeling for hydrologic analysis has greatly improved in recent years and the need for reliable gridded SWE datasets is paramount in evaluating dam safety, flood risk, and many other study purposes. Gridded SWE datasets are becoming common across the United States; however, the methods for creating and manipulating this data are not consistent across all datasets making it difficult to select an appropriate dataset.

This study evaluates two gridded SWE datasets: Snow Data Assimilation System (SNODAS) and University of Arizona (UA) for the Bighorn River basin in Wyoming and Montana. A general comparison of the two datasets will be presented. The Bighorn River basin includes a combination of plains and mountainous regions to compare different types of snowpack and snowmelt. The gridded SWE products will be compared against each other and against other existing point datasets. A comparison of accumulation, snowmelt rate and patterns, and hydrologic runoff volume resulting from melting snow will also be analyzed.