The University of Washington Hydrological Forecast System is a collection of tools, models, and configuration files to implement hydrological forecasts for specific areas and locations. The system forecasts hydrological characteristics such as soil moisture, snow and streamflow based on observed, modeled and forecasted meteorological conditions. Most of the data files needed for the implementation of a an actual forecast system are not included, since they are typically rather voluminous.

Implementations of the UW Hydro Forecast System serve as a research testbed to investigate hydrological forecasts methods and their characteristics. The system has been developed and implemented by the Surface Water Hydrology Group at the University of Washington. Visit the web site for more information. Depending on ongoing research activties, one or more functioning forecast systems may be found under the research heading on the web site. The web site also includes an extensive list of publications by the group, including a large number dealing with forecast methods and their characteristics.

If you intend to use code from this repository for your own forecast system, please see the LICENSE.md file.

Of particular interest are the following publications:

• Bohn, T.J., M.Y. Sonessa, and D.P. Lettenmaier, 2010: Seasonal hydrologic forecasting: Do multi-model ensemble averages always yield improvements in forecast skill?, J. Hydromet., 11(6), 1357-1371, doi:10.1175/2010JHM1267.1.

• Shi, X., A.W. Wood and D.P. Lettenmaier, 2008: How essential is hydrologic model calibration to seasonal streamflow forecasting?, J. of Hydrometeorology 9(6), 1350-1363, doi:10.1175/2008JHM1001.1.

• Shukla, S. and D. P. Lettenmaier, 2011: Seasonal hydrologic prediction in the United States: understanding the role of initial hydrologic conditions and seasonal climate forecast skill, Hydrol. Earth Syst. Sci., 15, 3529-3538, doi:10.5194/hess-15-3529-2011.

• Shukla, S., N. Voisin, and D. P. Lettenmaier, 2012:Value of medium range weather forecasts in the improvement of seasonal hydrologic prediction skill, Hydrol. Earth Syst. Sci., 16, 2825-2838, doi:10.5194/hess-16-2825-2012

• Voisin, N., F. Pappenberger, D.P. Lettenmaier, R. Buizza, and J.C. Schaake, 2011: Application of a medium range global hydrologic probabilistic forecast system to the Ohio River Basin, Weather And Forecasting 26, 425-446 doi:10.1175/WAF-D-10-05032.1.

• Voisin, N., J.C. Schaake, and D.P. Lettenmaier, 2010 Calibration and downscaling methods for quantitative ensemble precipitation forecasts, Weather And Forecasting, 25 (6), pp 1603-1627, doi:10.1175/2010WAF2222367.1.

• Wood, A.W. and D.P. Lettenmaier, 2006: A testbed for new seasonal hydrologic forecasting approaches in the western U.S., Bulletin of the American Meteorological Society, 87(12), 1699-1712, doi:10.1175/BAMS-87-12-1699.

The code for implementing and running a forecast system is contained in the following directories:

• config: configuration settings for the models to be used and the individual forecast projects. Each forecasting system can make forecasts for a large number of individual forecast projects.
• models: hydrological and routing models. This code may not belong here as part of the repository, because the various models typically have their own source code repositories. However, in some cases, changes have been made to the original models so that they can function as part of the forecast system
• runtime: The operational part of the forecast system. These are the version of the scripts and tools that are used at runtime, but they cannot be edited directly. Scripts and tools are installed by running the appropriate setup command first.
• setup: setup and configuration scripts to deploy a new forecasting system and to add new projects
• tools: the actual code and scripts that form a forecast system

Surface Water Hydrology Group University of Washington