Experimental Forecast Archive
Alan F. Hamlet
JISAO Climate Impacts Group
Department of Civil and Environmental Engineering
University of Washington
Revised 10/28/98
The retrospective streamflow forecasts available here are based on driving data for the hydrology model from 1948-1988. Thus there is no overlap of the driving data and the retrospective forecast period. The forecasts assume perfect foreknowledge of the ENSO state in June preceding the water year, based on the observed December-February Nino3.4 index (+-0.5 standard deviations from the mean). The PDO state is assumed to persist from the previous year unless an April-September average streamflow event in excess of 1.5 standard deviations from the long-term mean in opposition to the dominant phase of the PDO occurs, in which case the phase of the PDO is assumed to change. In the retrospective forecasts below, the PDO is assumed to shift from warm phase following the high flow event in water year 1997. Water year 1997 is assumed to be warm phase PDO, since this is the information available in June of 1996. Note that the forecast ensembles contain different numbers of ensemble members for different climate categories since these climate states have different frequencies in the period from 1948-1988.
To display a retrospective forecast click on the links below, which are identified by water year.
