Reclamation Information Sharing Environment (RISE)

Recent decades have experienced strong trends in hydrometeorology in the western US with declining watershed runoff efficiency, which may be undermining the accuracy of conventional seasonal streamflow prediction methods that support water supply forecasts. There is a critical need to develop strategies to enhance the reliability of seasonal streamflow prediction methods so that they to continue to provide accurate, unbiased and reliable predictions by accounting for such variability. This project created an unusually detailed modeling and ESP prediction (hindcast) resource that helped to understand new strategies for water supply prediction in the Upper Rio Grande River basin. It was generated to have specific relevance to the URGWOM management model. A key finding from the project analysis is that ESP-based approaches to water supply volume disaggregation is likely to be viable as an operational strategy for Reclamation, and that ESP-based sequences were more on average more skillful than analog-based sequences. Additional analysis into climate predictability in the western US suggested that sub-seasonal to seasonal climate forecasts may have the potential to offset streamflow predictability losses due to warming trends and declining snowpack.