CNRFC Water Supply

Monthly Water Supply Outlook - California and northern Nevada

The Water Supply Outlook for California and northern Nevada is issued January through May by the California Nevada River Forecast Center, National Weather Service. It represents a coordinated forecast effort between the National Weather Service, the California Department of Water Resources, the National Resource Conservation Service, the U.S. Bureau of Reclamation, and local water district managers.

All forecast volumes reflect natural flow. Actual observed flow may be affected by upstream water management.

All Monthly Water Supply Outlooks and verification products are published in .pdf format (requires Adobe® Acrobat Reader). A shorter text version that contains forecasts only is also available.

Western Water Supply Forecasts

Western Water Supply Forecasts - The new and improved web site allows water resource managers to use powerful new interactive forecasting tools to show expected seasonal water volumes at over 500 locations in the western United States. These new tools will allow users to see the probability of a stream producing a given seasonal water volume. The interactive capability allows users to generate future runoff scenarios based on historical observed precipitation and temperatures, or from an ensemble of previous years. In addition, the skill of forecasts which were made during previous years can be verified by comparing them to observed values.

Current Monthly Water Supply Outlooks

May 2008 Water Supply Outlook (full report - pdf format) - issued May 08, 2008
May 2008 Water Supply Outlook (text only) - issued May 07, 2008

Klamath Basin Mid-Month April Water Supply Outlook -- issued April 16, 2008
East Side Sierra Nevada Mid-Month April Water Supply Outlook -- issued April 11, 2008

Historical Archive - Monthly Water Supply Outlooks and Annual Verification

*special June update for Klamath and East-side Sierra Nevada

Statewide Water Conditions is now available on the CDEC website and contains a series of links to hmtl, text, and pdf format reports.

The web page Water Supply Outlook for the western United States hosted by the CBRFC presents a broader picture of water supply outlook conditions for the western United States, including:

- graphical and tabular streamflow forecasts
- monthly and seasonal precipitation
- mountain snowpack and satellite areal extent of snow cover
- reservoir storage

It is issued jointly by the National Weather Service and the USDA Natural Resources Conservation Service.

Runoff volume forecasts for the snowmelt season are seasonal products, issued weekly from about mid-April until peak stages occur (typically early to mid June). Indicated values are unimpaired flow volumes in thousands of acre-feet in 5 day intervals for the next 20 days. Runoff forecasts are updated every Wednesday during the snowmelt season and are published in .pdf format (requires Adobe® Acrobat Reader).

Snowmelt Runoff Volume Forecast - issued Wed, May 07, 2008

Previous Snowmelt Runoff Volume Forecasts issued duing the 2008 season are listed below with links to each document.

• April 16, 2008
• April 23, 2008
• April 30, 2008

7-Day Max/Min Temperature Data - updated daily. This product contains latest NWS temperature guidance and is a combination of official max/min temperatures issued by the NWS offices and Model Output Statistics (MOS) guidance from the NWS GFS model. The forecast temperature data is an important input to the runoff models.