Improving Forecasting for California's Snow Melt Water Supply

Science Center Objects

California's Sierra Nevada snowpack accounts for much of the water supply in many parts of the state. The snowpack retains large amounts of water in the winter that is then released as temperatures rise in the spring and summer. The snowpack also keeps the Sierra soil moist by covering it longer into spring and summer. Soil moisture influences the onset of wildfires, as well as wildfire prevalence and severity. In addition, much of the hydro-electric power in California is reliant on water supplied by the melting snowpack.

WERC High Sierra's

Snow Melting High in the Sierra Nevada's

Seeking new and innovative approaches to improve forecasting ability for the water supply generated from the snowpack, the USGS California Water Science Center has partnered with the  California Department of Water Resources to improve the data used to estimate spring snowmelt and runoff, and to develop products useful for forecasting water-supply needs under extreme conditions, such as drought.

This work includes:

  1. Revising high-resolution precipitation estimates to benefit seasonal runoff forecasting
  2. Revising soil-moisture parameterization to improve seasonal forecast simulation
  3. Evaluating and developing a soil-moisture monitoring strategy
  4. Assimilating Jet Propulsion Laboratory snow-water equivalent estimates into the Basin Characterization Model for water-balance simulations
  5. Developing situational status maps to support emergency response intelligence activities 

These efforts will not only help improve forecasting ability, but also inform emergency response planning. The proposed work addresses several aspects of the USGS Science Strategy for the Decade, 2007-2017 (U.S. Geological Survey, 2007), specifically "Understanding Ecosystems and Predicting Ecosystem Change, Climate Variability and Change."

Results for this work will be published in a journal article on the influence of spring snowmelt on soil. A model version, with accompanying documentation, will be delivered to the California Department of Water Resources. The model assimilates snow-water-equivalent data and updates the Basin Characterization Model monthly. These updates will be available on a website with drought conditions for water supply, the landscape, and wildfire.