About Us

The California-Nevada River Forecast Center (CNRFC) is a field office of the National Weather Service (NWS) located in Sacramento, California. The NWS is an agency of the National Oceanic Atmospheric and Administration (NOAA) under the United States Department of Commerce.

This mission of the NWS Hydrologic Services Program is to:

- Provide river and flood forecasts and warnings for the protection of lives and property.
- Provide basic hydrologic forecast information for the nation’s environmental and economic well being.

The NWS accomplishes its mission through 125 Weather Forecast Offices (WFOs), 13 River Forecast Centers (RFCs), and 5 National Centers for environmental Prediction (NCEP). These field offices are administratively and technically supported by Regional and National headquarters.

The NWS River Forecast Centers have four basic functions:

- Continuous hydrometeorological data assimilation, river basin modeling, and hydrologic forecast preparation.
- Technical support and interaction with supported and supporting NWS offices.
- Technical support and interaction with outside water management agencies and users.
- Applied research, development, and technological implementation to facilitate and support the above functions.

Figure 1 - Map of River Forecast Centers

The hydrologic area of responsibility for the CNRFC is shown in Figure 1 above. This area, of approximately 245,000 square miles, exhibits extreme variation in hydrologic regimes, supports large population centers, and is highly environmentally sensitive. Extreme pressure is placed on the areas water resources. WFOs associated with this area are located in Medford, OR, Eureka, Sacramento, Monterey, Hanford, Oxnard, and San Diego, CA, and Reno, Elko, and Las Vegas, NV. The CNRFC is supported by and in turn supports these WFOs (Figure 2).

Figure 2 - Map of NWS Forecast Offices
in the CNRFC Area of Responsibility

The CNRFC provides hydrologic guidance for time scales that vary from hours (flash flood guidance and support to Local Flood Warning Systems), to days (traditional flood forecasts), to weeks (snowmelt forecasts), to months (seasonal water supply) as shown in Figure 3 below.

Figure 3 - Hydrologic guidance time scale

To develop this guidance the CNRFC employs a host of hydrologic models and procedures that range from simple to complex and empirical to process-simulation (Figure 4.).

Figure 4. Time scale applications of
hydrologic models and procedures

The CNRFC is firmly committed to providing the best possible river forecast guidance to its customers. Improvements come in the form of expanded coverage and increased quality. Efforts are continuously underway to improve the process used to forecast flooding, spring snowmelt, and water supply volumes.