HR: 1340h
AN: H43B-1224    [Abstracts]
TI: Ensemble Hindcasts for the North Fork of the American River, California
AU: * Schaake, J
EM: john.schaake@noaa.gov
AF: Contractor, NOAA, NWS, Office of Hydrologic Development, 1A3 Spa Creek Landing, Annapolis, MD 21403, United States
AU: Hartman, R
EM: robert.harman@noaa.gov
AF: NOAA, NWS, California - Nevada River forecast Center, 3310 El Camino Ave, Room 227, Sacramento, CA 95821, United States
AU: Demargne, J
EM: julie.demargne@noaa.gov
AF: University Corporation for Atmospheric Reswearch and NOAA, NWS, Office of Hydrologic Development, 1325 East West Highway, Silver Spring, MD 20910, United States
AB: This presentation analyzes two sets of ensemble hindcasts for the North Fork of the American River. The North Fork of the American River drains from the Sierra Nevada Mountains and is an unregulated tributary to Folsom reservoir upstream from Sacramento. Two sets of hindcasts were made. One set uses historical climatological precipitation and temperature forcing. The other uses ensemble predictions from a fixed version of the National Centers for Environmental Predict (NCEP) Global Forecast System (GFS) for the first 14 days of lead time. The results of the climatological forcing hindcasts show the relative importance of intial conditions versus future forcing as a function of time of year and forecast lead time. The GFS forecasts substantially improve the skill of the forecasts during most of the first 30 days during the winter precipitation season. But uncertainty in initial conditions clearly limits the reliability of probabilistic forecasts for the first few days. The results show the importance of having a post-processor to correct for bias and spread errors that may occur in the raw model output.
DE: 1821 Floods
DE: 1840 Hydrometeorology
DE: 1847 Modeling
DE: 1860 Streamflow
DE: 1869 Stochastic hydrology
SC: Hydrology [H]
MN: 2007 Fall Meeting