Seasonal Streamflow Forecast Intercomparison Project


A small set of watersheds is being implemented for the intercomparison of various elements involved in seasonal streamflow forecasting approaches. The watersheds selected for the effort are relatively unimpaired basins that are important for water resources management. Each watershed (and including associated data and methods) is contributed by a partner in the project.

Intercomparison Results

Click an analysis type in the table below display intercomparison results.

Case Study Watershed Details and Data

Click a basin name in the table below display the data and forecasts for that basin.

Project Overview

Seasonal streamflow forecasts are produced operationally in many countries around the world to support decisionmaking in water management. Although there are many commonalities in the forecasting approaches, the approaches also use a range of methods, models and data. HEPEX is undertaking a project to develop a shared understanding of the strengths and weaknesses of modern strategies though intercomparing elements of the different approaches in a small number of forecasting basins around the world.


(1) Probabilistic forecasts streamflow or runoff volumes at lead times up to one year.
(2) Standard forecasts are for 1-month, 3-month periods. Other seasonal periods may be defined, e.g., snow melt and monsoonal periods.


(1) To learn from each other, share and improve techniques and expertise related to seasonal streamflow prediction.
(2) To test and compare the performance of seasonal hydrological forecasting systems in varied hydro-climatic zones.
(3) Encourage reproducibility of results and share methods
(4) To identify unique sources of skill in different forecasting systems
(5) To make publically available sets of ensemble hydrological re-forecasts for other applications


  Current Draft of SSFIP Protocol

Lead Contacts

  Andy Wood (NCAR) and Andrew Schepen (CSIRO)


  CSIRO: James Bennett, QJ Wang, Andrew Robertson (CSIRO)
  NCAR: Pablo Mendoza
  SMHI: Ilias Pechlivanidis
  CEH: Christel Prudhomme
  Irstea: Maria-Helena Ramos
  ECMWF: Fredrik Wetterhall
  Your Institution: You?

The Hydrologic Ensemble Prediction Experiment (HEPEX) is a community of research and practice to advance the use of ensemble methods in streamflow and hydrologic prediction. It is a volunteer initiative in which many people collaborate on various topics related to hydrological forecasting for practical or operational applications

HEPEX focuses on science challenges that are critical to improve the value of ensemble forecasts for risk-based decisionmaking by engaging in several kinds of ongoing activities, including:

  • organizing scientific exchange between participants through workshops and sessions or meetings at major conferences
  • planning and coordinating experiments or testbeds
  • highlighting operational or experimental examples of HEPS to raise awareness across the practice
  • maintaining a community online interaction and HEPS-related resources via the HEPEX website.

The HEPEX website (link at right) provides a forum for members to share their research, announcements, workshop reports, project findingss, and hear about related research and operational challenges.

Participation in HEPEX is open to anyone wishing to contribute to its objectives. Individuals interested in becoming involved in HEPEX can do so through participation in HEPEX activities, and particularly workshops (which are typically free).