HR: 1340h
AN: H13G-1389    [Abstracts]
TI: Forecast Quality of AHPS Ensemble Streamflow Predictions for the North Central River Forecast Center
AU: * Bradley, A
EM: allen-bradley@uiowa.edu
AF: The University of Iowa, IIHR-Hydroscience & Engineering, 107 Hydraulics Laboratory, Iowa City, IA 52242 United States
AU: Schwartz, S
EM: s.schwartz1@csuohio.edu
AF: Cleveland State University, Department of Civil and Environmental Engineering, 2121 Euclid Avenue, Cleveland, OH 44115 United States
AU: Kruger, A
EM: anton-kruger@uiowa.edu
AF: The University of Iowa, IIHR-Hydroscience & Engineering, 107 Hydraulics Laboratory, Iowa City, IA 52242 United States
AB: At the National Weather Service (NWS) North Central River Forecast Center (NCRFC), Advanced Hydrologic Prediction Services (AHPS) have been implemented for seasonal streamflow forecasting. AHPS uses ensemble streamflow prediction (ESP) techniques to make forecasts of the conditional probability distribution of streamflow variables over a forecast window of up to 90 days. For selected sites in the NCRFC, we assess the quality of AHPS forecasts of seasonal minimum and maximum flows, and flow volumes. First, retrospective forecasts (or hindcasts) are generated for a period from 1950 to 1996. The forecasts are then paired with available streamflow observations for forecast verification. An extension of the distributions-oriented (DO) approach is used for diagnostic verification. The approach assesses the quality of ensemble predictions as probabilistic forecasts over the range of possible outcomes, including the forecast probability of extreme low-flow or high-flow events. The large variation in the quality of ensemble predictions over the range of outcomes is a significant aspect of ensemble predictions, and is demonstrated using measures of bias, skill, and other attributes. We also examine the sampling uncertainty of DO forecast quality measures, and its impact on making inferences about the forecast quality for extreme events of interest in water resources management.
DE: 1817 Extreme events
DE: 1833 Hydroclimatology
DE: 1860 Streamflow
DE: 1873 Uncertainty assessment (3275)
DE: 1880 Water management (6334)
SC: Hydrology [H]
MN: Fall Meeting 2005