Reclamation Information Sharing Environment (RISE)

In basins dominated by snowmelt during the spring and early summer, runoff forecast methods often rely on snowpack information from spatial products with coarse resolution (1 km) and/or in-situ observations across limited geographic locations both of which are not always representative of basin snow conditions. However, accurate characterization of snow water equivalent (SWE) requires representing its spatial variability across the basin scale with sufficiently fine spatial resolution to account for important processes that drive seasonal snowpack evolution. This study developed 30-m SnowModel simulations across the Big Thompson River, Three Lakes, and Willow Creek Basins, Colorado (4,212 km2) for water years 2000 through 2023 and evaluated the incorporation of remotely sensed snow-covered area (SCA) datasets into model development and calibration. Results show that versions of SnowModel calibrated to remotely sensed SCA had improved performance over baseline simulations especially at the highest elevations. This study also developed a near real-time modeling approach that couples remotely sensed SCA data at 30-m resolution with the calibrated SnowModel simulations to further improve the spatial distribution of simulated snow across the study basins. This near-real time tool will be used to support runoff forecasting methods in future runoff seasons.