Research

Hydrology and Water Resources: Current Research

Developing New Medium- to Long-Range Columbia Basin Streamflow Forecasting Methods

Personnel

• Alan Hamlet (contact person)
• Dennis Lettenmaier

Background

Medium- to long-range climate forecasting, based on real time ensemble forecasts of the Madden Julian Oscillation and the Pacific North America Pattern, has continued to develop to the point where there appears to be sufficient skill to produce useful shifts in the probability distributions of ensemble streamflow forecasts for the Columbia River at lead times of about two weeks to one month. These forecasts are expected to be most useful in mid-winter when precipitation signals are strongest, but may also be useful at other times of the year.

Research Questions

• What medium-range climate forecasts are useful for streamflow prediction in the Pacific Northwest?
• How can the linkages between various climate forecasting products and hydrologic models best be constructed?
• How much can these experimental forecasts improve upon existing forecast products based, for example, on El Niño/Southern Oscillation forecasts?
• How can various kinds of forecast information be optimally combined to produce the highest forecast skill?
• What are the error characteristics of experimental medium-range forecasts?