Link to CIG Homepage

Seminar Abstract

Andy Wood - June 10, 2003
with co-authors Alan Hamlet and Dennis Lettenmaier


Implementing Real-Time Seasonal Hydrologic Forecasting for the Western U.S.: Recent Progress

We are implementing an experimental end-to-end hydrologic forecasting approach that uses ensemble climate forecasts to drive the Variable Infiltration Capacity (VIC) macroscale hydrologic model for the large river basins of the western U.S., producing streamflow forecasts for lead times of six months to a year. Climate forecast ensembles are derived from several climate models, and also formulated via the Extended Streamflow Prediction
(ESP) method; and the ESP forecasts are further composited to provide ENSO and PDO conditioned ensembles. The forecasting project began real-time (2-week) updates in the end of December, 2002, and ran through April 2003, over a limited initial domain of the Pacific Northwest. In that time, several improvements were pursued, including the development of an assimilation of snow water equivalent observations at the start of the forecast, and a modification of the surface forcing estimation immediately prior to the forecast start. In addition, a retrospective forecast skill analysis over the entire western U.S. domain was undertaken to ascertain the value of the climate model forecasts, relative to the ESP forecast baseline and climatological forecasts. Results from the real-time and retrospective forecast efforts will be discussed, along with the directions anticipated for expanding the real time forecast system.

Back to top | CIG Home