National Weather Service California Nevada River Forecast Center Department of Commerce National Oceanic and Atmospheric Administration National Weather Service

HEFS - Hydrologic Ensemble Forecast Service

The Hydrologic Ensemble Forecast Service is an initiative from the National Weather Service (NWS) to provide short-term and long-term probabilistic hydrologic forecasts to the various users of hydrologic information, such as NWS Weather Forecast Offices (WFOs), local emergency management officials, reservoir operators, and other water resources managers. The data in the products is based on analysis of historic precipitation, temperature and streamflow, current river and basin conditions, and short-term meteorologic forecasts.

Topic Description
HEFS at CNRFC Detailed documentation regarding the implementation of HEFS at CNRFC

HEFS Trace Analysis - "Build Your Own" Product

The HEFS Trace Analysis interface provides great flexibility in deriving products and information from the available ensemble streamflow traces. Please select from the topics in the table below to learn more about HEFS Trace Analysis and how to use the "Build Your Own" product interface.

Topic Description
General Ensemble Theory for Streamflow Forecasts A very general overview of HEFS and the trace analysis product.
HEFS Trace Analysis - Making Selections and Interpreting Results Specific instructions on how to "build your own product" and intrepret the results
HEFS - A Few Words of Caution A review of the current limitations of HEFS as interpreted at the CNRFC

To create your own product go directly to the HEFS Trace Analysis Interface